diff --git a/stage0/src/kernel/cache_stack.h b/stage0/src/kernel/cache_stack.h
deleted file mode 100644
index 1c16f29103..0000000000
--- a/stage0/src/kernel/cache_stack.h
+++ /dev/null
@@ -1,41 +0,0 @@
-/*
-Copyright (c) 2013 Microsoft Corporation. All rights reserved.
-Released under Apache 2.0 license as described in the file LICENSE.
-
-Author: Leonardo de Moura
-*/
-#pragma once
-#include <vector>
-#include <memory>
-#include "runtime/debug.h"
-
-/** \brief Macro for creating a stack of objects of type Cache in thread local storage.
-    The argument \c Arg is provided to every new instance of Cache.
-    The macro provides the helper class Cache_ref that "reuses" cache objects from the stack.
-*/
-#define MK_CACHE_STACK(Cache, Arg)                                      \
-struct Cache ## _stack {                                                \
-    unsigned                                     m_top;                 \
-    std::vector<std::unique_ptr<Cache>> m_cache_stack;                  \
-    Cache ## _stack():m_top(0) {}                                       \
-};                                                                      \
-MK_THREAD_LOCAL_GET_DEF(Cache ## _stack, get_ ## Cache ## _stack);      \
-class Cache ## _ref {                                                   \
-    Cache * m_cache;                                                    \
-public:                                                                 \
-    Cache ## _ref() {                                                   \
-        Cache ## _stack & s = get_ ## Cache ## _stack();                \
-        lean_assert(s.m_top <= s.m_cache_stack.size());                 \
-        if (s.m_top == s.m_cache_stack.size())                          \
-            s.m_cache_stack.push_back(std::unique_ptr<Cache>(new Cache(Arg))); \
-        m_cache = s.m_cache_stack[s.m_top].get();                       \
-        s.m_top++;                                                      \
-    }                                                                   \
-    ~Cache ## _ref() {                                                  \
-        Cache ## _stack & s = get_ ## Cache ## _stack();                \
-        lean_assert(s.m_top > 0);                                       \
-        s.m_top--;                                                      \
-        m_cache->clear();                                               \
-    }                                                                   \
-    Cache * operator->() const { return m_cache; }                      \
-};
diff --git a/stage0/src/kernel/replace_fn.cpp b/stage0/src/kernel/replace_fn.cpp
index f0b995d6d1..23883f1d8b 100644
--- a/stage0/src/kernel/replace_fn.cpp
+++ b/stage0/src/kernel/replace_fn.cpp
@@ -6,75 +6,35 @@ Author: Leonardo de Moura
 */
 #include <vector>
 #include <memory>
+#include <unordered_map>
 #include "kernel/replace_fn.h"
-#include "kernel/cache_stack.h"
-
-#ifndef LEAN_DEFAULT_REPLACE_CACHE_CAPACITY
-#define LEAN_DEFAULT_REPLACE_CACHE_CAPACITY 1024*8
-#endif
 
 namespace lean {
-struct replace_cache {
-    struct entry {
-        object  *  m_cell;
-        unsigned   m_offset;
-        expr       m_result;
-        entry():m_cell(nullptr) {}
-    };
-    unsigned              m_capacity;
-    std::vector<entry>    m_cache;
-    std::vector<unsigned> m_used;
-    replace_cache(unsigned c):m_capacity(c), m_cache(c) {}
-
-    expr * find(expr const & e, unsigned offset) {
-        unsigned i = hash(hash(e), offset) % m_capacity;
-        if (m_cache[i].m_cell == e.raw() && m_cache[i].m_offset == offset)
-            return &m_cache[i].m_result;
-        else
-            return nullptr;
-    }
-
-    void insert(expr const & e, unsigned offset, expr const & v) {
-        unsigned i = hash(hash(e), offset) % m_capacity;
-        if (m_cache[i].m_cell == nullptr)
-            m_used.push_back(i);
-        m_cache[i].m_cell   = e.raw();
-        m_cache[i].m_offset = offset;
-        m_cache[i].m_result = v;
-    }
-
-    void clear() {
-        for (unsigned i : m_used) {
-            m_cache[i].m_cell   = nullptr;
-            m_cache[i].m_result = expr();
-        }
-        m_used.clear();
-    }
-};
-
-/* CACHE_RESET: NO */
-MK_CACHE_STACK(replace_cache, LEAN_DEFAULT_REPLACE_CACHE_CAPACITY)
 
 class replace_rec_fn {
-    replace_cache_ref                                     m_cache;
+    struct key_hasher {
+        std::size_t operator()(std::pair<lean_object *, unsigned> const & p) const {
+            return hash((size_t)p.first, p.second);
+        }
+    };
+    std::unordered_map<std::pair<lean_object *, unsigned>, expr, key_hasher> m_cache;
     std::function<optional<expr>(expr const &, unsigned)> m_f;
     bool                                                  m_use_cache;
 
     expr save_result(expr const & e, unsigned offset, expr const & r, bool shared) {
         if (shared)
-            m_cache->insert(e, offset, r);
+            m_cache.insert(mk_pair(mk_pair(e.raw(), offset), r));
         return r;
     }
 
     expr apply(expr const & e, unsigned offset) {
         bool shared = false;
         if (m_use_cache && is_shared(e)) {
-            if (auto r = m_cache->find(e, offset))
-                return *r;
+            auto it = m_cache.find(mk_pair(e.raw(), offset));
+            if (it != m_cache.end())
+                return it->second;
             shared = true;
         }
-        check_system("replace");
-
         if (optional<expr> r = m_f(e, offset)) {
             return save_result(e, offset, *r, shared);
         } else {
@@ -121,4 +81,73 @@ public:
 expr replace(expr const & e, std::function<optional<expr>(expr const &, unsigned)> const & f, bool use_cache) {
     return replace_rec_fn(f, use_cache)(e);
 }
+
+class replace_fn {
+    std::unordered_map<lean_object *, expr> m_cache;
+    lean_object * m_f;
+
+    expr save_result(expr const & e, expr const & r, bool shared) {
+        if (shared)
+            m_cache.insert(mk_pair(e.raw(), r));
+        return r;
+    }
+
+    expr apply(expr const & e) {
+        bool shared = false;
+        if (is_shared(e)) {
+            auto it = m_cache.find(e.raw());
+            if (it != m_cache.end())
+                return it->second;
+            shared = true;
+        }
+
+        lean_inc(e.raw());
+        lean_inc_ref(m_f);
+        lean_object * r = lean_apply_1(m_f, e.raw());
+        if (!lean_is_scalar(r)) {
+            expr e_new(lean_ctor_get(r, 0));
+            lean_dec_ref(r);
+            return save_result(e, e_new, shared);
+        }
+
+        switch (e.kind()) {
+        case expr_kind::Const: case expr_kind::Sort:
+        case expr_kind::BVar:  case expr_kind::Lit:
+        case expr_kind::MVar:  case expr_kind::FVar:
+            return save_result(e, e, shared);
+        case expr_kind::MData: {
+            expr new_e = apply(mdata_expr(e));
+            return save_result(e, update_mdata(e, new_e), shared);
+        }
+        case expr_kind::Proj: {
+            expr new_e = apply(proj_expr(e));
+            return save_result(e, update_proj(e, new_e), shared);
+        }
+        case expr_kind::App: {
+            expr new_f = apply(app_fn(e));
+            expr new_a = apply(app_arg(e));
+            return save_result(e, update_app(e, new_f, new_a), shared);
+        }
+        case expr_kind::Pi: case expr_kind::Lambda: {
+            expr new_d = apply(binding_domain(e));
+            expr new_b = apply(binding_body(e));
+            return save_result(e, update_binding(e, new_d, new_b), shared);
+        }
+        case expr_kind::Let: {
+            expr new_t = apply(let_type(e));
+            expr new_v = apply(let_value(e));
+            expr new_b = apply(let_body(e));
+            return save_result(e, update_let(e, new_t, new_v, new_b), shared);
+        }}
+        lean_unreachable();
+    }
+public:
+    replace_fn(lean_object * f):m_f(f) {}
+    expr operator()(expr const & e) { return apply(e); }
+};
+
+extern "C" LEAN_EXPORT obj_res lean_replace_expr(b_obj_arg f, b_obj_arg e) {
+    expr r = replace_fn(f)(TO_REF(expr, e));
+    return r.steal();
+}
 }
diff --git a/stage0/stdlib/Lean/AddDecl.c b/stage0/stdlib/Lean/AddDecl.c
index c7f8cf5bc9..032d2c5a9d 100644
--- a/stage0/stdlib/Lean/AddDecl.c
+++ b/stage0/stdlib/Lean/AddDecl.c
@@ -2761,14 +2761,12 @@ if (x_9 == 0)
 {
 uint8_t x_10; uint8_t x_11; 
 x_10 = 0;
-lean_inc(x_1);
 x_11 = l_Lean_Declaration_foldExprM___at_Lean_Declaration_hasSorry___spec__1(x_1, x_10);
 if (x_11 == 0)
 {
 lean_object* x_12; lean_object* x_13; 
 x_12 = lean_box(0);
 x_13 = l_Lean_addDecl___lambda__2(x_1, x_12, x_2, x_3, x_7);
-lean_dec(x_1);
 return x_13;
 }
 else
@@ -2784,7 +2782,6 @@ lean_inc(x_17);
 lean_dec(x_15);
 x_18 = l_Lean_addDecl___lambda__2(x_1, x_16, x_2, x_3, x_17);
 lean_dec(x_16);
-lean_dec(x_1);
 return x_18;
 }
 }
@@ -2793,7 +2790,6 @@ else
 lean_object* x_19; lean_object* x_20; 
 x_19 = lean_box(0);
 x_20 = l_Lean_addDecl___lambda__2(x_1, x_19, x_2, x_3, x_7);
-lean_dec(x_1);
 return x_20;
 }
 }
@@ -3053,6 +3049,7 @@ _start:
 lean_object* x_5; 
 x_5 = l_Lean_addDecl___lambda__3(x_1, x_2, x_3, x_4);
 lean_dec(x_3);
+lean_dec(x_1);
 return x_5;
 }
 }
diff --git a/stage0/stdlib/Lean/Compiler/InlineAttrs.c b/stage0/stdlib/Lean/Compiler/InlineAttrs.c
index 3315d6dbae..51e3e10361 100644
--- a/stage0/stdlib/Lean/Compiler/InlineAttrs.c
+++ b/stage0/stdlib/Lean/Compiler/InlineAttrs.c
@@ -103,7 +103,6 @@ lean_object* l_Lean_MessageData_ofExpr(lean_object*);
 LEAN_EXPORT lean_object* l_Lean_Compiler_initFn____x40_Lean_Compiler_InlineAttrs___hyg_267____lambda__1___boxed(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 static lean_object* l_Lean_Compiler_initFn____x40_Lean_Compiler_InlineAttrs___hyg_267____lambda__1___closed__1;
 LEAN_EXPORT lean_object* l___private_Lean_Compiler_InlineAttrs_0__Lean_Compiler_hasInlineAttrAux___boxed(lean_object*, lean_object*, lean_object*);
-lean_object* l_Lean_Expr_FindImpl_findUnsafe_x3f(lean_object*, lean_object*);
 LEAN_EXPORT uint8_t l___private_Lean_Compiler_InlineAttrs_0__Lean_Compiler_hasInlineAttrAux(lean_object*, uint8_t, lean_object*);
 static lean_object* l_Lean_Compiler_initFn____x40_Lean_Compiler_InlineAttrs___hyg_267____closed__15;
 static lean_object* l_Lean_Compiler_setInlineAttribute___closed__1;
@@ -137,6 +136,7 @@ LEAN_EXPORT lean_object* l_Lean_Compiler_InlineAttributeKind_noConfusion(lean_ob
 static lean_object* l_Lean_Compiler_initFn____x40_Lean_Compiler_InlineAttrs___hyg_267____closed__30;
 static lean_object* l_Lean_getConstInfo___at___private_Lean_Compiler_InlineAttrs_0__Lean_Compiler_isValidMacroInline___spec__1___closed__4;
 uint8_t l_Lean_isAuxRecursorWithSuffix(lean_object*, lean_object*, lean_object*);
+lean_object* lean_find_expr(lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_Compiler_getInlineAttribute_x3f(lean_object*, lean_object*);
 uint8_t lean_is_eager_lambda_lifting_name(lean_object*);
 static lean_object* l_Lean_Compiler_initFn____x40_Lean_Compiler_InlineAttrs___hyg_267____closed__1;
@@ -665,9 +665,8 @@ x_13 = lean_alloc_closure((void*)(l___private_Lean_Compiler_InlineAttrs_0__Lean_
 lean_closure_set(x_13, 0, x_11);
 lean_closure_set(x_13, 1, x_1);
 x_14 = lean_ctor_get(x_2, 1);
-lean_inc(x_14);
-lean_dec(x_2);
-x_15 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_13, x_14);
+x_15 = lean_find_expr(x_13, x_14);
+lean_dec(x_13);
 if (lean_obj_tag(x_15) == 0)
 {
 lean_object* x_16; lean_object* x_17; 
@@ -704,9 +703,8 @@ x_24 = lean_alloc_closure((void*)(l___private_Lean_Compiler_InlineAttrs_0__Lean_
 lean_closure_set(x_24, 0, x_22);
 lean_closure_set(x_24, 1, x_1);
 x_25 = lean_ctor_get(x_2, 1);
-lean_inc(x_25);
-lean_dec(x_2);
-x_26 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_24, x_25);
+x_26 = lean_find_expr(x_24, x_25);
+lean_dec(x_24);
 if (lean_obj_tag(x_26) == 0)
 {
 lean_object* x_27; lean_object* x_28; 
@@ -779,6 +777,7 @@ lean_object* x_17; lean_object* x_18;
 lean_free_object(x_5);
 x_17 = lean_box(0);
 x_18 = l___private_Lean_Compiler_InlineAttrs_0__Lean_Compiler_isValidMacroInline___lambda__3(x_1, x_10, x_17, x_2, x_3, x_8);
+lean_dec(x_10);
 return x_18;
 }
 }
@@ -817,6 +816,7 @@ else
 lean_object* x_28; lean_object* x_29; 
 x_28 = lean_box(0);
 x_29 = l___private_Lean_Compiler_InlineAttrs_0__Lean_Compiler_isValidMacroInline___lambda__3(x_1, x_20, x_28, x_2, x_3, x_19);
+lean_dec(x_20);
 return x_29;
 }
 }
@@ -928,6 +928,7 @@ _start:
 lean_object* x_7; 
 x_7 = l___private_Lean_Compiler_InlineAttrs_0__Lean_Compiler_isValidMacroInline___lambda__3(x_1, x_2, x_3, x_4, x_5, x_6);
 lean_dec(x_3);
+lean_dec(x_2);
 return x_7;
 }
 }
diff --git a/stage0/stdlib/Lean/CoreM.c b/stage0/stdlib/Lean/CoreM.c
index 4458550095..4e0e46c6dd 100644
--- a/stage0/stdlib/Lean/CoreM.c
+++ b/stage0/stdlib/Lean/CoreM.c
@@ -435,7 +435,6 @@ static lean_object* l_Lean_withTraceNode___at_Lean_compileDecl___spec__2___lambd
 static lean_object* l_Lean_initFn____x40_Lean_CoreM___hyg_43____closed__5;
 static lean_object* l_Lean_initFn____x40_Lean_CoreM___hyg_43____closed__3;
 static lean_object* l_Lean_withTraceNode___at_Lean_compileDecl___spec__2___lambda__3___closed__2;
-lean_object* l_Lean_Expr_FindImpl_findUnsafe_x3f(lean_object*, lean_object*);
 static lean_object* l_List_foldlM___at___private_Lean_CoreM_0__Lean_checkUnsupported___spec__2___rarg___lambda__2___closed__4;
 static lean_object* l_Lean_useDiagnosticMsg___closed__2;
 LEAN_EXPORT lean_object* l_Lean_Core_instMonadLogCoreM___lambda__4___boxed(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
@@ -618,6 +617,7 @@ LEAN_EXPORT lean_object* l_Lean_Core_withCurrHeartbeats___rarg(lean_object*, lea
 LEAN_EXPORT lean_object* l_Lean_Core_withRestoreOrSaveFull(lean_object*);
 LEAN_EXPORT lean_object* l_Lean_ImportM_runCoreM(lean_object*);
 uint8_t lean_level_eq(lean_object*, lean_object*);
+lean_object* lean_find_expr(lean_object*, lean_object*);
 uint8_t lean_nat_dec_le(lean_object*, lean_object*);
 uint8_t lean_usize_dec_lt(size_t, size_t);
 LEAN_EXPORT lean_object* l_Lean_Core_instInhabitedCache;
@@ -13223,9 +13223,7 @@ _start:
 {
 lean_object* x_6; lean_object* x_7; 
 x_6 = lean_ctor_get(x_1, 1);
-lean_inc(x_6);
-lean_dec(x_1);
-x_7 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_2, x_6);
+x_7 = lean_find_expr(x_2, x_6);
 if (lean_obj_tag(x_7) == 0)
 {
 lean_object* x_8; lean_object* x_9; lean_object* x_10; lean_object* x_11; 
@@ -13327,8 +13325,8 @@ lean_dec(x_13);
 lean_inc(x_3);
 x_15 = lean_alloc_closure((void*)(l_List_foldlM___at___private_Lean_CoreM_0__Lean_checkUnsupported___spec__2___rarg___lambda__1___boxed), 2, 1);
 lean_closure_set(x_15, 0, x_3);
-lean_inc(x_15);
-x_16 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_15, x_14);
+x_16 = lean_find_expr(x_15, x_14);
+lean_dec(x_14);
 lean_inc(x_2);
 lean_inc(x_1);
 x_17 = lean_alloc_closure((void*)(l_List_foldlM___at___private_Lean_CoreM_0__Lean_checkUnsupported___spec__2___rarg___lambda__2___boxed), 5, 4);
@@ -13427,8 +13425,8 @@ lean_dec(x_43);
 lean_inc(x_3);
 x_45 = lean_alloc_closure((void*)(l_List_foldlM___at___private_Lean_CoreM_0__Lean_checkUnsupported___spec__2___rarg___lambda__1___boxed), 2, 1);
 lean_closure_set(x_45, 0, x_3);
-lean_inc(x_45);
-x_46 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_45, x_44);
+x_46 = lean_find_expr(x_45, x_44);
+lean_dec(x_44);
 lean_inc(x_2);
 lean_inc(x_1);
 x_47 = lean_alloc_closure((void*)(l_List_foldlM___at___private_Lean_CoreM_0__Lean_checkUnsupported___spec__2___rarg___lambda__2___boxed), 5, 4);
@@ -13558,8 +13556,8 @@ lean_inc(x_12);
 x_13 = lean_ctor_get(x_10, 1);
 lean_inc(x_13);
 lean_dec(x_10);
-lean_inc(x_3);
-x_14 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_3, x_13);
+x_14 = lean_find_expr(x_3, x_13);
+lean_dec(x_13);
 lean_inc(x_2);
 lean_inc(x_1);
 x_15 = lean_alloc_closure((void*)(l_List_foldlM___at___private_Lean_CoreM_0__Lean_checkUnsupported___spec__3___rarg___lambda__1), 5, 4);
@@ -13640,8 +13638,8 @@ lean_inc(x_36);
 x_37 = lean_ctor_get(x_34, 1);
 lean_inc(x_37);
 lean_dec(x_34);
-lean_inc(x_3);
-x_38 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_3, x_37);
+x_38 = lean_find_expr(x_3, x_37);
+lean_dec(x_37);
 lean_inc(x_2);
 lean_inc(x_1);
 x_39 = lean_alloc_closure((void*)(l_List_foldlM___at___private_Lean_CoreM_0__Lean_checkUnsupported___spec__3___rarg___lambda__1), 5, 4);
@@ -13771,8 +13769,8 @@ lean_inc(x_13);
 lean_inc(x_3);
 x_14 = lean_alloc_closure((void*)(l_List_foldlM___at___private_Lean_CoreM_0__Lean_checkUnsupported___spec__2___rarg___lambda__1___boxed), 2, 1);
 lean_closure_set(x_14, 0, x_3);
-lean_inc(x_14);
-x_15 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_14, x_13);
+x_15 = lean_find_expr(x_14, x_13);
+lean_dec(x_13);
 lean_inc(x_2);
 lean_inc(x_1);
 x_16 = lean_alloc_closure((void*)(l_List_foldlM___at___private_Lean_CoreM_0__Lean_checkUnsupported___spec__4___rarg___lambda__1), 5, 4);
@@ -13868,8 +13866,8 @@ lean_inc(x_42);
 lean_inc(x_3);
 x_43 = lean_alloc_closure((void*)(l_List_foldlM___at___private_Lean_CoreM_0__Lean_checkUnsupported___spec__2___rarg___lambda__1___boxed), 2, 1);
 lean_closure_set(x_43, 0, x_3);
-lean_inc(x_43);
-x_44 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_43, x_42);
+x_44 = lean_find_expr(x_43, x_42);
+lean_dec(x_42);
 lean_inc(x_2);
 lean_inc(x_1);
 x_45 = lean_alloc_closure((void*)(l_List_foldlM___at___private_Lean_CoreM_0__Lean_checkUnsupported___spec__4___rarg___lambda__1), 5, 4);
@@ -13963,7 +13961,7 @@ LEAN_EXPORT lean_object* l_Lean_Declaration_foldExprM___at___private_Lean_CoreM_
 _start:
 {
 lean_object* x_6; 
-x_6 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_1, x_2);
+x_6 = lean_find_expr(x_1, x_2);
 if (lean_obj_tag(x_6) == 0)
 {
 lean_object* x_7; lean_object* x_8; lean_object* x_9; lean_object* x_10; 
@@ -14039,7 +14037,9 @@ lean_inc(x_8);
 lean_dec(x_7);
 x_9 = lean_alloc_closure((void*)(l_List_foldlM___at___private_Lean_CoreM_0__Lean_checkUnsupported___spec__2___rarg___lambda__1___boxed), 2, 1);
 lean_closure_set(x_9, 0, x_3);
-x_10 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_9, x_8);
+x_10 = lean_find_expr(x_9, x_8);
+lean_dec(x_8);
+lean_dec(x_9);
 if (lean_obj_tag(x_10) == 0)
 {
 lean_object* x_11; lean_object* x_12; lean_object* x_13; lean_object* x_14; 
@@ -14146,8 +14146,8 @@ x_38 = lean_ctor_get(x_1, 1);
 lean_inc(x_38);
 x_39 = lean_alloc_closure((void*)(l_List_foldlM___at___private_Lean_CoreM_0__Lean_checkUnsupported___spec__2___rarg___lambda__1___boxed), 2, 1);
 lean_closure_set(x_39, 0, x_3);
-lean_inc(x_39);
-x_40 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_39, x_37);
+x_40 = lean_find_expr(x_39, x_37);
+lean_dec(x_37);
 lean_inc(x_2);
 lean_inc(x_1);
 x_41 = lean_alloc_closure((void*)(l_Lean_Declaration_foldExprM___at___private_Lean_CoreM_0__Lean_checkUnsupported___spec__1___rarg___lambda__1___boxed), 5, 4);
@@ -14273,6 +14273,8 @@ _start:
 lean_object* x_6; 
 x_6 = l_List_foldlM___at___private_Lean_CoreM_0__Lean_checkUnsupported___spec__2___rarg___lambda__2(x_1, x_2, x_3, x_4, x_5);
 lean_dec(x_5);
+lean_dec(x_2);
+lean_dec(x_1);
 return x_6;
 }
 }
@@ -14282,6 +14284,8 @@ _start:
 lean_object* x_6; 
 x_6 = l_Lean_Declaration_foldExprM___at___private_Lean_CoreM_0__Lean_checkUnsupported___spec__1___rarg___lambda__1(x_1, x_2, x_3, x_4, x_5);
 lean_dec(x_5);
+lean_dec(x_2);
+lean_dec(x_1);
 return x_6;
 }
 }
@@ -16254,7 +16258,9 @@ lean_dec(x_32);
 lean_inc(x_1);
 x_34 = lean_alloc_closure((void*)(l_List_foldlM___at___private_Lean_CoreM_0__Lean_checkUnsupported___spec__2___rarg___lambda__1___boxed), 2, 1);
 lean_closure_set(x_34, 0, x_1);
-x_35 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_34, x_33);
+x_35 = lean_find_expr(x_34, x_33);
+lean_dec(x_33);
+lean_dec(x_34);
 if (lean_obj_tag(x_35) == 0)
 {
 x_11 = x_6;
@@ -16321,7 +16327,9 @@ lean_dec(x_8);
 lean_inc(x_1);
 x_13 = lean_alloc_closure((void*)(l_List_foldlM___at___private_Lean_CoreM_0__Lean_checkUnsupported___spec__2___rarg___lambda__1___boxed), 2, 1);
 lean_closure_set(x_13, 0, x_1);
-x_14 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_13, x_12);
+x_14 = lean_find_expr(x_13, x_12);
+lean_dec(x_12);
+lean_dec(x_13);
 if (lean_obj_tag(x_14) == 0)
 {
 lean_object* x_15; 
@@ -16424,7 +16432,9 @@ lean_dec(x_9);
 lean_inc(x_1);
 x_12 = lean_alloc_closure((void*)(l_List_foldlM___at___private_Lean_CoreM_0__Lean_checkUnsupported___spec__2___rarg___lambda__1___boxed), 2, 1);
 lean_closure_set(x_12, 0, x_1);
-x_13 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_12, x_11);
+x_13 = lean_find_expr(x_12, x_11);
+lean_dec(x_11);
+lean_dec(x_12);
 if (lean_obj_tag(x_13) == 0)
 {
 lean_object* x_14; 
@@ -16503,7 +16513,9 @@ lean_dec(x_29);
 lean_inc(x_1);
 x_32 = lean_alloc_closure((void*)(l_List_foldlM___at___private_Lean_CoreM_0__Lean_checkUnsupported___spec__2___rarg___lambda__1___boxed), 2, 1);
 lean_closure_set(x_32, 0, x_1);
-x_33 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_32, x_31);
+x_33 = lean_find_expr(x_32, x_31);
+lean_dec(x_31);
+lean_dec(x_32);
 if (lean_obj_tag(x_33) == 0)
 {
 lean_object* x_34; 
@@ -16598,7 +16610,9 @@ lean_inc(x_20);
 lean_inc(x_1);
 x_21 = lean_alloc_closure((void*)(l_List_foldlM___at___private_Lean_CoreM_0__Lean_checkUnsupported___spec__2___rarg___lambda__1___boxed), 2, 1);
 lean_closure_set(x_21, 0, x_1);
-x_22 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_21, x_20);
+x_22 = lean_find_expr(x_21, x_20);
+lean_dec(x_20);
+lean_dec(x_21);
 if (lean_obj_tag(x_22) == 0)
 {
 lean_object* x_23; lean_object* x_24; lean_object* x_25; 
@@ -16725,7 +16739,9 @@ lean_inc(x_51);
 lean_inc(x_1);
 x_52 = lean_alloc_closure((void*)(l_List_foldlM___at___private_Lean_CoreM_0__Lean_checkUnsupported___spec__2___rarg___lambda__1___boxed), 2, 1);
 lean_closure_set(x_52, 0, x_1);
-x_53 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_52, x_51);
+x_53 = lean_find_expr(x_52, x_51);
+lean_dec(x_51);
+lean_dec(x_52);
 if (lean_obj_tag(x_53) == 0)
 {
 lean_object* x_54; lean_object* x_55; lean_object* x_56; 
@@ -16862,7 +16878,9 @@ lean_inc(x_9);
 lean_dec(x_8);
 x_10 = lean_alloc_closure((void*)(l_List_foldlM___at___private_Lean_CoreM_0__Lean_checkUnsupported___spec__2___rarg___lambda__1___boxed), 2, 1);
 lean_closure_set(x_10, 0, x_1);
-x_11 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_10, x_9);
+x_11 = lean_find_expr(x_10, x_9);
+lean_dec(x_9);
+lean_dec(x_10);
 if (lean_obj_tag(x_11) == 0)
 {
 lean_object* x_12; lean_object* x_13; 
@@ -16926,7 +16944,9 @@ lean_dec(x_25);
 lean_inc(x_1);
 x_44 = lean_alloc_closure((void*)(l_List_foldlM___at___private_Lean_CoreM_0__Lean_checkUnsupported___spec__2___rarg___lambda__1___boxed), 2, 1);
 lean_closure_set(x_44, 0, x_1);
-x_45 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_44, x_27);
+x_45 = lean_find_expr(x_44, x_27);
+lean_dec(x_27);
+lean_dec(x_44);
 if (lean_obj_tag(x_45) == 0)
 {
 x_28 = x_6;
@@ -16987,7 +17007,9 @@ block_43:
 lean_object* x_29; lean_object* x_30; 
 x_29 = lean_alloc_closure((void*)(l_List_foldlM___at___private_Lean_CoreM_0__Lean_checkUnsupported___spec__2___rarg___lambda__1___boxed), 2, 1);
 lean_closure_set(x_29, 0, x_1);
-x_30 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_29, x_26);
+x_30 = lean_find_expr(x_29, x_26);
+lean_dec(x_26);
+lean_dec(x_29);
 if (lean_obj_tag(x_30) == 0)
 {
 lean_object* x_31; lean_object* x_32; 
@@ -17052,7 +17074,9 @@ lean_dec(x_59);
 lean_inc(x_1);
 x_78 = lean_alloc_closure((void*)(l_List_foldlM___at___private_Lean_CoreM_0__Lean_checkUnsupported___spec__2___rarg___lambda__1___boxed), 2, 1);
 lean_closure_set(x_78, 0, x_1);
-x_79 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_78, x_61);
+x_79 = lean_find_expr(x_78, x_61);
+lean_dec(x_61);
+lean_dec(x_78);
 if (lean_obj_tag(x_79) == 0)
 {
 x_62 = x_6;
@@ -17113,7 +17137,9 @@ block_77:
 lean_object* x_63; lean_object* x_64; 
 x_63 = lean_alloc_closure((void*)(l_List_foldlM___at___private_Lean_CoreM_0__Lean_checkUnsupported___spec__2___rarg___lambda__1___boxed), 2, 1);
 lean_closure_set(x_63, 0, x_1);
-x_64 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_63, x_60);
+x_64 = lean_find_expr(x_63, x_60);
+lean_dec(x_60);
+lean_dec(x_63);
 if (lean_obj_tag(x_64) == 0)
 {
 lean_object* x_65; lean_object* x_66; 
@@ -17178,7 +17204,9 @@ lean_dec(x_93);
 lean_inc(x_1);
 x_112 = lean_alloc_closure((void*)(l_List_foldlM___at___private_Lean_CoreM_0__Lean_checkUnsupported___spec__2___rarg___lambda__1___boxed), 2, 1);
 lean_closure_set(x_112, 0, x_1);
-x_113 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_112, x_95);
+x_113 = lean_find_expr(x_112, x_95);
+lean_dec(x_95);
+lean_dec(x_112);
 if (lean_obj_tag(x_113) == 0)
 {
 x_96 = x_6;
@@ -17239,7 +17267,9 @@ block_111:
 lean_object* x_97; lean_object* x_98; 
 x_97 = lean_alloc_closure((void*)(l_List_foldlM___at___private_Lean_CoreM_0__Lean_checkUnsupported___spec__2___rarg___lambda__1___boxed), 2, 1);
 lean_closure_set(x_97, 0, x_1);
-x_98 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_97, x_94);
+x_98 = lean_find_expr(x_97, x_94);
+lean_dec(x_94);
+lean_dec(x_97);
 if (lean_obj_tag(x_98) == 0)
 {
 lean_object* x_99; lean_object* x_100; 
diff --git a/stage0/stdlib/Lean/Elab/App.c b/stage0/stdlib/Lean/Elab/App.c
index 846c3723f8..1ce21a24c9 100644
--- a/stage0/stdlib/Lean/Elab/App.c
+++ b/stage0/stdlib/Lean/Elab/App.c
@@ -841,7 +841,6 @@ LEAN_EXPORT lean_object* l___private_Lean_Elab_App_0__Lean_Elab_Term_ElabAppArgs
 LEAN_EXPORT lean_object* l___private_Lean_Elab_App_0__Lean_Elab_Term_elabAppFnId_toLVals(lean_object*, lean_object*, uint8_t);
 LEAN_EXPORT lean_object* l___private_Lean_Elab_App_0__Lean_Elab_Term_throwInvalidFieldNotation___rarg(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 static lean_object* l_Array_foldlMUnsafe_fold___at_Lean_Elab_Term_ElabAppArgs_trySynthesizeAppInstMVars___spec__2___closed__1;
-lean_object* l_Lean_Expr_FindImpl_findUnsafe_x3f(lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_List_map___at_Lean_Elab_Term_elabAppArgs___spec__1___at_Lean_Elab_Term_elabAppArgs___spec__2(lean_object*, lean_object*, lean_object*);
 static lean_object* l___regBuiltin_Lean_Elab_Term_elabChoice__1___closed__2;
 LEAN_EXPORT lean_object* l_Lean_Meta_forallTelescopeReducing___at___private_Lean_Elab_App_0__Lean_Elab_Term_ElabAppArgs_anyNamedArgDependsOnCurrent___spec__19(lean_object*);
@@ -1159,6 +1158,7 @@ LEAN_EXPORT lean_object* l___private_Lean_Elab_App_0__Lean_Elab_Term_ElabAppArgs
 LEAN_EXPORT lean_object* l_Lean_Elab_Term_mkFreshBinderName___at_Lean_Elab_Term_ElabElim_mkMotive___spec__1___rarg___lambda__1(lean_object*, lean_object*, lean_object*, lean_object*);
 lean_object* lean_infer_type(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 static lean_object* l___private_Lean_Elab_App_0__Lean_Elab_Term_resolveDotName_go___closed__4;
+lean_object* lean_find_expr(lean_object*, lean_object*);
 LEAN_EXPORT uint8_t l_Lean_PersistentArray_anyM___at___private_Lean_Elab_App_0__Lean_Elab_Term_ElabAppArgs_anyNamedArgDependsOnCurrent___spec__13(lean_object*, lean_object*);
 uint8_t lean_nat_dec_le(lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_Elab_Term_elabAppArgs_elabAsElim_x3f___lambda__2___boxed(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
@@ -27985,7 +27985,7 @@ _start:
 {
 lean_object* x_2; lean_object* x_3; 
 x_2 = l_Lean_Elab_Term_elabAppArgs_isFirstOrder___closed__1;
-x_3 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_2, x_1);
+x_3 = lean_find_expr(x_2, x_1);
 if (lean_obj_tag(x_3) == 0)
 {
 uint8_t x_4; 
@@ -28016,6 +28016,7 @@ _start:
 {
 uint8_t x_2; lean_object* x_3; 
 x_2 = l_Lean_Elab_Term_elabAppArgs_isFirstOrder(x_1);
+lean_dec(x_1);
 x_3 = lean_box(x_2);
 return x_3;
 }
@@ -28078,7 +28079,6 @@ lean_inc(x_32);
 x_33 = lean_ctor_get(x_31, 1);
 lean_inc(x_33);
 lean_dec(x_31);
-lean_inc(x_32);
 x_34 = l_Lean_Elab_Term_elabAppArgs_isFirstOrder(x_32);
 if (x_34 == 0)
 {
@@ -28096,7 +28096,9 @@ lean_object* x_36; lean_object* x_37;
 lean_inc(x_3);
 x_36 = lean_alloc_closure((void*)(l_Std_Range_forIn_loop___at_Lean_Elab_Term_elabAppArgs_getElabAsElimExtraArgsPos___spec__1___lambda__1___boxed), 2, 1);
 lean_closure_set(x_36, 0, x_3);
-x_37 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_36, x_32);
+x_37 = lean_find_expr(x_36, x_32);
+lean_dec(x_32);
+lean_dec(x_36);
 if (lean_obj_tag(x_37) == 0)
 {
 lean_object* x_38; 
@@ -28197,7 +28199,6 @@ lean_inc(x_51);
 x_52 = lean_ctor_get(x_50, 1);
 lean_inc(x_52);
 lean_dec(x_50);
-lean_inc(x_51);
 x_53 = l_Lean_Elab_Term_elabAppArgs_isFirstOrder(x_51);
 if (x_53 == 0)
 {
@@ -28215,7 +28216,9 @@ lean_object* x_55; lean_object* x_56;
 lean_inc(x_3);
 x_55 = lean_alloc_closure((void*)(l_Std_Range_forIn_loop___at_Lean_Elab_Term_elabAppArgs_getElabAsElimExtraArgsPos___spec__1___lambda__1___boxed), 2, 1);
 lean_closure_set(x_55, 0, x_3);
-x_56 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_55, x_51);
+x_56 = lean_find_expr(x_55, x_51);
+lean_dec(x_51);
+lean_dec(x_55);
 if (lean_obj_tag(x_56) == 0)
 {
 lean_object* x_57; 
diff --git a/stage0/stdlib/Lean/Elab/ComputedFields.c b/stage0/stdlib/Lean/Elab/ComputedFields.c
index 5d026eeb58..e74bfd001b 100644
--- a/stage0/stdlib/Lean/Elab/ComputedFields.c
+++ b/stage0/stdlib/Lean/Elab/ComputedFields.c
@@ -1177,7 +1177,6 @@ if (x_52 == 0)
 lean_object* x_53; lean_object* x_54; uint8_t x_55; 
 x_53 = lean_ctor_get(x_51, 0);
 x_54 = lean_ctor_get(x_51, 1);
-lean_inc(x_53);
 lean_inc(x_1);
 x_55 = l_Lean_Expr_occurs(x_1, x_53);
 if (x_55 == 0)
@@ -1285,7 +1284,6 @@ x_70 = lean_ctor_get(x_51, 1);
 lean_inc(x_70);
 lean_inc(x_69);
 lean_dec(x_51);
-lean_inc(x_69);
 lean_inc(x_1);
 x_71 = l_Lean_Expr_occurs(x_1, x_69);
 if (x_71 == 0)
@@ -1435,7 +1433,6 @@ if (x_91 == 0)
 lean_object* x_92; lean_object* x_93; uint8_t x_94; 
 x_92 = lean_ctor_get(x_90, 0);
 x_93 = lean_ctor_get(x_90, 1);
-lean_inc(x_92);
 lean_inc(x_1);
 x_94 = l_Lean_Expr_occurs(x_1, x_92);
 if (x_94 == 0)
@@ -1543,7 +1540,6 @@ x_109 = lean_ctor_get(x_90, 1);
 lean_inc(x_109);
 lean_inc(x_108);
 lean_dec(x_90);
-lean_inc(x_108);
 lean_inc(x_1);
 x_110 = l_Lean_Expr_occurs(x_1, x_108);
 if (x_110 == 0)
@@ -1693,7 +1689,6 @@ if (x_130 == 0)
 lean_object* x_131; lean_object* x_132; uint8_t x_133; 
 x_131 = lean_ctor_get(x_129, 0);
 x_132 = lean_ctor_get(x_129, 1);
-lean_inc(x_131);
 lean_inc(x_1);
 x_133 = l_Lean_Expr_occurs(x_1, x_131);
 if (x_133 == 0)
@@ -1801,7 +1796,6 @@ x_148 = lean_ctor_get(x_129, 1);
 lean_inc(x_148);
 lean_inc(x_147);
 lean_dec(x_129);
-lean_inc(x_147);
 lean_inc(x_1);
 x_149 = l_Lean_Expr_occurs(x_1, x_147);
 if (x_149 == 0)
@@ -1960,7 +1954,6 @@ if (x_171 == 0)
 lean_object* x_172; lean_object* x_173; uint8_t x_174; 
 x_172 = lean_ctor_get(x_170, 0);
 x_173 = lean_ctor_get(x_170, 1);
-lean_inc(x_172);
 lean_inc(x_1);
 x_174 = l_Lean_Expr_occurs(x_1, x_172);
 if (x_174 == 0)
@@ -2068,7 +2061,6 @@ x_189 = lean_ctor_get(x_170, 1);
 lean_inc(x_189);
 lean_inc(x_188);
 lean_dec(x_170);
-lean_inc(x_188);
 lean_inc(x_1);
 x_190 = l_Lean_Expr_occurs(x_1, x_188);
 if (x_190 == 0)
@@ -2320,7 +2312,6 @@ if (x_11 == 0)
 lean_object* x_12; lean_object* x_13; uint8_t x_14; 
 x_12 = lean_ctor_get(x_10, 0);
 x_13 = lean_ctor_get(x_10, 1);
-lean_inc(x_12);
 x_14 = l_Lean_Expr_occurs(x_1, x_12);
 if (x_14 == 0)
 {
@@ -2354,7 +2345,6 @@ x_18 = lean_ctor_get(x_10, 1);
 lean_inc(x_18);
 lean_inc(x_17);
 lean_dec(x_10);
-lean_inc(x_17);
 x_19 = l_Lean_Expr_occurs(x_1, x_17);
 if (x_19 == 0)
 {
diff --git a/stage0/stdlib/Lean/Elab/MutualDef.c b/stage0/stdlib/Lean/Elab/MutualDef.c
index 8a3e8c5597..65cec306dd 100644
--- a/stage0/stdlib/Lean/Elab/MutualDef.c
+++ b/stage0/stdlib/Lean/Elab/MutualDef.c
@@ -706,7 +706,6 @@ LEAN_EXPORT lean_object* l_Array_forInUnsafe_loop___at___private_Lean_Elab_Mutua
 LEAN_EXPORT lean_object* l_Lean_RBNode_find___at___private_Lean_Elab_MutualDef_0__Lean_Elab_Term_MutualClosure_mkLetRecClosureFor___spec__4___boxed(lean_object*, lean_object*);
 static lean_object* l_Array_mapMUnsafe_map___at___private_Lean_Elab_MutualDef_0__Lean_Elab_Term_expandWhereStructInst___spec__5___lambda__2___closed__5;
 lean_object* l_Lean_LocalDecl_fvarId(lean_object*);
-lean_object* l_Lean_Expr_FindExtImpl_findUnsafe_x3f(lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l___private_Lean_Elab_MutualDef_0__Lean_Elab_Term_MutualClosure_FixPoint_resetModified___rarg(lean_object*);
 LEAN_EXPORT lean_object* l_Array_mapMUnsafe_map___at___private_Lean_Elab_MutualDef_0__Lean_Elab_Term_levelMVarToParamHeaders___spec__1(size_t, size_t, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_addTrace___at___private_Lean_Elab_MutualDef_0__Lean_Elab_Term_MutualClosure_mkClosureForAux___spec__5___boxed(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
@@ -719,6 +718,7 @@ LEAN_EXPORT lean_object* l_Array_forInUnsafe_loop___at___private_Lean_Elab_Mutua
 static lean_object* l_Array_mapMUnsafe_map___at___private_Lean_Elab_MutualDef_0__Lean_Elab_Term_expandWhereStructInst___spec__3___closed__1;
 LEAN_EXPORT lean_object* l_Lean_Elab_instInhabitedDefViewElabHeader;
 lean_object* l_Lean_CollectFVars_main(lean_object*, lean_object*);
+lean_object* lean_find_ext_expr(lean_object*, lean_object*);
 static lean_object* l_Lean_Elab_Command_initFn____x40_Lean_Elab_MutualDef___hyg_15660____closed__13;
 LEAN_EXPORT lean_object* l___private_Lean_Elab_MutualDef_0__Lean_Elab_Term_MutualClosure_preprocess(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 lean_object* l_Lean_Elab_Term_withAutoBoundImplicitForbiddenPred___rarg(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
@@ -806,7 +806,6 @@ lean_object* l_Lean_Elab_TerminationHints_rememberExtraParams(lean_object*, lean
 LEAN_EXPORT lean_object* l_Array_mapMUnsafe_map___at___private_Lean_Elab_MutualDef_0__Lean_Elab_Term_expandWhereStructInst___spec__5___lambda__4___boxed(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 static lean_object* l_Lean_Elab_Term_checkForHiddenUnivLevels_visitLevel___closed__12;
 lean_object* l_Lean_Meta_withLCtx___at___private_Lean_Meta_Basic_0__Lean_Meta_mkLeveErrorMessageCore___spec__2___rarg(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
-lean_object* l_Lean_Expr_FindImpl_findUnsafe_x3f(lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_Meta_withLocalDecl___at_Lean_Elab_Term_checkForHiddenUnivLevels_visit___spec__4___rarg___lambda__1(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Nat_foldM_loop___at_Lean_Elab_Term_MutualClosure_pushMain___spec__1___lambda__1(lean_object*, lean_object*, uint8_t, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 extern lean_object* l_Lean_Parser_Term_type;
@@ -1123,6 +1122,7 @@ LEAN_EXPORT lean_object* l_Lean_Elab_elabTerminationHints___at___private_Lean_El
 LEAN_EXPORT lean_object* l_Array_anyMUnsafe_any___at___private_Lean_Elab_MutualDef_0__Lean_Elab_Term_elabHeaders___spec__2___boxed(lean_object*, lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l___private_Lean_Elab_MutualDef_0__Lean_Elab_Term_check___boxed(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 lean_object* lean_infer_type(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
+lean_object* lean_find_expr(lean_object*, lean_object*);
 uint8_t lean_nat_dec_le(lean_object*, lean_object*);
 static lean_object* l_Lean_Core_withRestoreOrSaveFull___at___private_Lean_Elab_MutualDef_0__Lean_Elab_Term_elabHeaders___spec__6___lambda__5___closed__1;
 static lean_object* l_Lean_Elab_Term_checkForHiddenUnivLevels___closed__1;
@@ -1220,6 +1220,7 @@ static lean_object* l_Lean_Elab_elabModifiers___at_Lean_Elab_Command_elabMutualD
 LEAN_EXPORT lean_object* l_Array_mapMUnsafe_map___at_Lean_Elab_Command_elabMutualDef___spec__15___boxed(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Array_forInUnsafe_loop___at_Lean_Elab_Term_elabMutualDef_processDeriving___spec__2(lean_object*, size_t, size_t, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 static lean_object* l_Lean_Elab_Command_initFn____x40_Lean_Elab_MutualDef___hyg_15660____closed__11;
+LEAN_EXPORT lean_object* l___private_Lean_Elab_MutualDef_0__Lean_Elab_Term_typeHasRecFun___boxed(lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l___private_Lean_Elab_MutualDef_0__Lean_Elab_Term_MutualClosure_FixPoint_isModified(lean_object*);
 LEAN_EXPORT lean_object* l_Nat_foldTR_loop___at_Lean_Elab_Term_MutualClosure_insertReplacementForMainFns___spec__1___boxed(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Std_Range_forIn_x27_loop___at_Lean_Elab_Command_elabMutualDef___spec__12___lambda__2(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, uint8_t, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
@@ -22972,7 +22973,8 @@ lean_object* x_4; lean_object* x_5;
 x_4 = lean_alloc_closure((void*)(l___private_Lean_Elab_MutualDef_0__Lean_Elab_Term_typeHasRecFun___lambda__2___boxed), 3, 2);
 lean_closure_set(x_4, 0, x_2);
 lean_closure_set(x_4, 1, x_3);
-x_5 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_4, x_1);
+x_5 = lean_find_expr(x_4, x_1);
+lean_dec(x_4);
 if (lean_obj_tag(x_5) == 0)
 {
 lean_object* x_6; 
@@ -23053,6 +23055,15 @@ x_5 = lean_box(x_4);
 return x_5;
 }
 }
+LEAN_EXPORT lean_object* l___private_Lean_Elab_MutualDef_0__Lean_Elab_Term_typeHasRecFun___boxed(lean_object* x_1, lean_object* x_2, lean_object* x_3) {
+_start:
+{
+lean_object* x_4; 
+x_4 = l___private_Lean_Elab_MutualDef_0__Lean_Elab_Term_typeHasRecFun(x_1, x_2, x_3);
+lean_dec(x_1);
+return x_4;
+}
+}
 LEAN_EXPORT lean_object* l___private_Lean_Elab_MutualDef_0__Lean_Elab_Term_getFunName___lambda__1(lean_object* x_1, lean_object* x_2) {
 _start:
 {
@@ -23295,6 +23306,7 @@ lean_inc(x_16);
 lean_inc(x_2);
 lean_inc(x_1);
 x_17 = l___private_Lean_Elab_MutualDef_0__Lean_Elab_Term_typeHasRecFun(x_16, x_1, x_2);
+lean_dec(x_16);
 if (lean_obj_tag(x_17) == 0)
 {
 lean_free_object(x_3);
@@ -23397,6 +23409,7 @@ lean_inc(x_39);
 lean_inc(x_2);
 lean_inc(x_1);
 x_40 = l___private_Lean_Elab_MutualDef_0__Lean_Elab_Term_typeHasRecFun(x_39, x_1, x_2);
+lean_dec(x_39);
 if (lean_obj_tag(x_40) == 0)
 {
 lean_dec(x_37);
@@ -31259,7 +31272,8 @@ _start:
 lean_object* x_3; lean_object* x_4; 
 x_3 = lean_alloc_closure((void*)(l_Lean_Elab_Term_MutualClosure_isApplicable___lambda__1___boxed), 2, 1);
 lean_closure_set(x_3, 0, x_1);
-x_4 = l_Lean_Expr_FindExtImpl_findUnsafe_x3f(x_3, x_2);
+x_4 = lean_find_ext_expr(x_3, x_2);
+lean_dec(x_3);
 if (lean_obj_tag(x_4) == 0)
 {
 uint8_t x_5; 
@@ -31301,6 +31315,7 @@ _start:
 {
 uint8_t x_3; lean_object* x_4; 
 x_3 = l_Lean_Elab_Term_MutualClosure_isApplicable(x_1, x_2);
+lean_dec(x_2);
 x_4 = lean_box(x_3);
 return x_4;
 }
@@ -32271,7 +32286,6 @@ return x_6;
 else
 {
 uint8_t x_7; 
-lean_inc(x_2);
 lean_inc(x_1);
 x_7 = l_Lean_Elab_Term_MutualClosure_isApplicable(x_1, x_2);
 if (x_7 == 0)
diff --git a/stage0/stdlib/Lean/Elab/PreDefinition/Basic.c b/stage0/stdlib/Lean/Elab/PreDefinition/Basic.c
index 11ea99e0cc..87ebaad4eb 100644
--- a/stage0/stdlib/Lean/Elab/PreDefinition/Basic.c
+++ b/stage0/stdlib/Lean/Elab/PreDefinition/Basic.c
@@ -240,7 +240,6 @@ LEAN_EXPORT lean_object* l_Lean_Elab_withSaveInfoContext___at___private_Lean_Ela
 lean_object* l_Lean_Elab_Term_addTermInfo_x27(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, uint8_t, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 lean_object* l_Lean_Core_transform___at_Lean_Core_betaReduce___spec__1(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 static lean_object* l___private_Lean_Elab_PreDefinition_Basic_0__Lean_Elab_addNonRecAux___lambda__4___closed__7;
-lean_object* l_Lean_Expr_FindImpl_findUnsafe_x3f(lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_MonadExcept_ofExcept___at_Lean_Elab_shareCommonPreDefs___spec__4(lean_object*, lean_object*, lean_object*, lean_object*);
 static lean_object* l___private_Lean_Elab_PreDefinition_Basic_0__Lean_Elab_addNonRecAux___lambda__4___closed__2;
 static lean_object* l_Lean_Elab_fixLevelParams___closed__6;
@@ -331,6 +330,7 @@ static lean_object* l_Std_Range_forIn_loop___at_Lean_Elab_checkCodomainsLevel___
 LEAN_EXPORT lean_object* l_Std_Range_forIn_loop___at_Lean_Elab_checkCodomainsLevel___spec__2___lambda__2___boxed(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 static lean_object* l_Lean_Elab_shareCommonPreDefs___lambda__1___closed__1;
 lean_object* lean_infer_type(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
+lean_object* lean_find_expr(lean_object*, lean_object*);
 uint8_t lean_nat_dec_le(lean_object*, lean_object*);
 static lean_object* l___private_Lean_Elab_PreDefinition_Basic_0__Lean_Elab_getLevelParamsPreDecls___closed__1;
 LEAN_EXPORT lean_object* l_Lean_Elab_fixLevelParams___lambda__1(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
@@ -10410,7 +10410,8 @@ _start:
 lean_object* x_3; lean_object* x_4; 
 x_3 = lean_alloc_closure((void*)(l___private_Lean_Elab_PreDefinition_Basic_0__Lean_Elab_containsRecFn___lambda__1___boxed), 2, 1);
 lean_closure_set(x_3, 0, x_1);
-x_4 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_3, x_2);
+x_4 = lean_find_expr(x_3, x_2);
+lean_dec(x_3);
 if (lean_obj_tag(x_4) == 0)
 {
 uint8_t x_5; 
@@ -10442,6 +10443,7 @@ _start:
 {
 uint8_t x_3; lean_object* x_4; 
 x_3 = l___private_Lean_Elab_PreDefinition_Basic_0__Lean_Elab_containsRecFn(x_1, x_2);
+lean_dec(x_2);
 x_4 = lean_box(x_3);
 return x_4;
 }
@@ -10528,7 +10530,6 @@ LEAN_EXPORT lean_object* l_Lean_Elab_ensureNoRecFn(lean_object* x_1, lean_object
 _start:
 {
 uint8_t x_8; 
-lean_inc(x_2);
 lean_inc(x_1);
 x_8 = l___private_Lean_Elab_PreDefinition_Basic_0__Lean_Elab_containsRecFn(x_1, x_2);
 if (x_8 == 0)
diff --git a/stage0/stdlib/Lean/Elab/PreDefinition/Eqns.c b/stage0/stdlib/Lean/Elab/PreDefinition/Eqns.c
index b5494b9a3b..3fefe6053a 100644
--- a/stage0/stdlib/Lean/Elab/PreDefinition/Eqns.c
+++ b/stage0/stdlib/Lean/Elab/PreDefinition/Eqns.c
@@ -39,6 +39,7 @@ LEAN_EXPORT lean_object* l_Lean_Elab_Eqns_whnfReducibleLHS_x3f___lambda__1(lean_
 static lean_object* l_Lean_Elab_Eqns_deltaLHS___lambda__2___closed__6;
 LEAN_EXPORT lean_object* l_Lean_Elab_Eqns_initFn____x40_Lean_Elab_PreDefinition_Eqns___hyg_6521_(lean_object*);
 lean_object* l_Lean_commitWhen___at___private_Lean_Meta_Tactic_Contradiction_0__Lean_Meta_elimEmptyInductive___spec__1(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
+LEAN_EXPORT lean_object* l_Lean_Elab_Eqns_splitMatch_x3f_go___boxed(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_mkFreshId___at_Lean_Elab_Eqns_removeUnusedEqnHypotheses_go___spec__14(lean_object*);
 LEAN_EXPORT lean_object* l_Array_foldrMUnsafe_fold___at___private_Lean_Elab_PreDefinition_Eqns_0__Lean_Elab_Eqns_saveEqn___spec__22___boxed(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Array_foldrMUnsafe_fold___at___private_Lean_Elab_PreDefinition_Eqns_0__Lean_Elab_Eqns_saveEqn___spec__11___boxed(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
@@ -335,7 +336,7 @@ LEAN_EXPORT lean_object* l_Array_forInUnsafe_loop___at_Lean_Elab_Eqns_removeUnus
 lean_object* l_Lean_Meta_saveState___rarg(lean_object*, lean_object*, lean_object*, lean_object*);
 extern lean_object* l_Lean_diagnostics;
 lean_object* l_Lean_LocalDecl_fvarId(lean_object*);
-lean_object* l_Lean_Expr_FindExtImpl_findUnsafe_x3f(lean_object*, lean_object*);
+LEAN_EXPORT lean_object* l___private_Lean_Elab_PreDefinition_Eqns_0__Lean_Elab_Eqns_findMatchToSplit_x3f___boxed(lean_object*, lean_object*, lean_object*, lean_object*);
 lean_object* l_Lean_Expr_appFn_x21(lean_object*);
 LEAN_EXPORT lean_object* l_Lean_Elab_Eqns_simpIf_x3f(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_ForEachExpr_visit___at___private_Lean_Elab_PreDefinition_Eqns_0__Lean_Elab_Eqns_shouldUseSimpMatch___spec__2(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
@@ -347,6 +348,7 @@ lean_object* l_Lean_CollectFVars_main(lean_object*, lean_object*);
 static lean_object* l_Lean_Elab_Eqns_initFn____x40_Lean_Elab_PreDefinition_Eqns___hyg_6521____closed__19;
 static lean_object* l_Array_forInUnsafe_loop___at_Lean_Elab_Eqns_simpEqnType___spec__1___lambda__1___closed__1;
 LEAN_EXPORT lean_object* l_Lean_Elab_Eqns_mkEqnTypes(uint8_t, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
+lean_object* lean_find_ext_expr(lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l___private_Lean_Data_PersistentArray_0__Lean_PersistentArray_foldrMAux___at___private_Lean_Elab_PreDefinition_Eqns_0__Lean_Elab_Eqns_saveEqn___spec__21___boxed(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Array_forInUnsafe_loop___at_Lean_Elab_Eqns_simpEqnType___spec__1___lambda__2(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l___private_Lean_Elab_PreDefinition_Eqns_0__Lean_Elab_Eqns_findMatchToSplit_x3f___lambda__1___boxed(lean_object*);
@@ -388,7 +390,6 @@ LEAN_EXPORT lean_object* l_Array_forInUnsafe_loop___at_Lean_Elab_Eqns_removeUnus
 static lean_object* l___private_Lean_Elab_PreDefinition_Eqns_0__Lean_Elab_Eqns_saveEqn___closed__1;
 LEAN_EXPORT lean_object* l_Array_forInUnsafe_loop___at_Lean_Elab_Eqns_removeUnusedEqnHypotheses_go___spec__9___at_Lean_Elab_Eqns_removeUnusedEqnHypotheses_go___spec__10(lean_object*, lean_object*, size_t, size_t, lean_object*, lean_object*, lean_object*, lean_object*);
 lean_object* l_Lean_Meta_withLCtx___at___private_Lean_Meta_Basic_0__Lean_Meta_mkLeveErrorMessageCore___spec__2___rarg(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
-lean_object* l_Lean_Expr_FindImpl_findUnsafe_x3f(lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_ForEachExprWhere_checked___at_Lean_Elab_Eqns_simpEqnType_collect___spec__5(lean_object*);
 LEAN_EXPORT lean_object* l___private_Lean_Data_PersistentArray_0__Lean_PersistentArray_foldrMAux___at___private_Lean_Elab_PreDefinition_Eqns_0__Lean_Elab_Eqns_saveEqn___spec__15___boxed(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 lean_object* l_Lean_Meta_isConstructorApp(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
@@ -524,6 +525,7 @@ LEAN_EXPORT lean_object* l_Array_foldrMUnsafe_fold___at___private_Lean_Elab_PreD
 static lean_object* l_Lean_Elab_Eqns_splitMatch_x3f_go___closed__2;
 static lean_object* l_Lean_Elab_Eqns_initFn____x40_Lean_Elab_PreDefinition_Eqns___hyg_6521____closed__17;
 lean_object* lean_infer_type(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
+lean_object* lean_find_expr(lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_Meta_checkpointDefEq___at_Lean_Elab_Eqns_mkUnfoldProof___spec__2(lean_object*, lean_object*, uint8_t, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_Elab_Eqns_mkUnfoldProof_go___lambda__2(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 uint8_t lean_nat_dec_le(lean_object*, lean_object*);
@@ -2090,7 +2092,9 @@ if (x_15 == 0)
 lean_object* x_17; lean_object* x_18; lean_object* x_19; 
 x_17 = l_Lean_instInhabitedExpr;
 x_18 = l_outOfBounds___rarg(x_17);
-x_19 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_16, x_18);
+x_19 = lean_find_expr(x_16, x_18);
+lean_dec(x_18);
+lean_dec(x_16);
 if (lean_obj_tag(x_19) == 0)
 {
 lean_object* x_20; 
@@ -2121,7 +2125,9 @@ else
 {
 lean_object* x_23; lean_object* x_24; 
 x_23 = lean_array_fget(x_2, x_5);
-x_24 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_16, x_23);
+x_24 = lean_find_expr(x_16, x_23);
+lean_dec(x_23);
+lean_dec(x_16);
 if (lean_obj_tag(x_24) == 0)
 {
 lean_object* x_25; 
@@ -2417,7 +2423,8 @@ x_5 = lean_alloc_closure((void*)(l___private_Lean_Elab_PreDefinition_Eqns_0__Lea
 lean_closure_set(x_5, 0, x_4);
 lean_closure_set(x_5, 1, x_1);
 lean_closure_set(x_5, 2, x_3);
-x_6 = l_Lean_Expr_FindExtImpl_findUnsafe_x3f(x_5, x_2);
+x_6 = lean_find_ext_expr(x_5, x_2);
+lean_dec(x_5);
 return x_6;
 }
 }
@@ -2504,6 +2511,15 @@ lean_dec(x_1);
 return x_5;
 }
 }
+LEAN_EXPORT lean_object* l___private_Lean_Elab_PreDefinition_Eqns_0__Lean_Elab_Eqns_findMatchToSplit_x3f___boxed(lean_object* x_1, lean_object* x_2, lean_object* x_3, lean_object* x_4) {
+_start:
+{
+lean_object* x_5; 
+x_5 = l___private_Lean_Elab_PreDefinition_Eqns_0__Lean_Elab_Eqns_findMatchToSplit_x3f(x_1, x_2, x_3, x_4);
+lean_dec(x_2);
+return x_5;
+}
+}
 LEAN_EXPORT lean_object* l_Lean_Elab_Eqns_splitMatch_x3f_go___lambda__1(lean_object* x_1, lean_object* x_2, lean_object* x_3, lean_object* x_4, lean_object* x_5, lean_object* x_6) {
 _start:
 {
@@ -2608,13 +2624,11 @@ lean_inc(x_14);
 lean_dec(x_12);
 lean_inc(x_4);
 lean_inc(x_2);
-lean_inc(x_3);
 x_15 = l___private_Lean_Elab_PreDefinition_Eqns_0__Lean_Elab_Eqns_findMatchToSplit_x3f(x_14, x_3, x_2, x_4);
 if (lean_obj_tag(x_15) == 0)
 {
 lean_object* x_16; lean_object* x_17; uint8_t x_18; 
 lean_dec(x_4);
-lean_dec(x_3);
 lean_dec(x_2);
 x_16 = l_Lean_Elab_Eqns_splitMatch_x3f_go___closed__4;
 x_17 = l_Lean_isTracingEnabledFor___at_Lean_Meta_processPostponed_loop___spec__1(x_16, x_5, x_6, x_7, x_8, x_13);
@@ -2729,7 +2743,6 @@ lean_dec(x_7);
 lean_dec(x_6);
 lean_dec(x_5);
 lean_dec(x_4);
-lean_dec(x_3);
 lean_dec(x_2);
 lean_dec(x_1);
 x_49 = !lean_is_exclusive(x_48);
@@ -2789,7 +2802,6 @@ lean_dec(x_7);
 lean_dec(x_6);
 lean_dec(x_5);
 lean_dec(x_4);
-lean_dec(x_3);
 lean_dec(x_2);
 lean_dec(x_1);
 return x_48;
@@ -2803,7 +2815,6 @@ lean_dec(x_7);
 lean_dec(x_6);
 lean_dec(x_5);
 lean_dec(x_4);
-lean_dec(x_3);
 lean_dec(x_2);
 lean_dec(x_1);
 return x_48;
@@ -2840,7 +2851,6 @@ lean_dec(x_7);
 lean_dec(x_6);
 lean_dec(x_5);
 lean_dec(x_4);
-lean_dec(x_3);
 lean_dec(x_2);
 lean_dec(x_1);
 x_67 = lean_alloc_ctor(1, 2, 0);
@@ -2858,7 +2868,6 @@ lean_dec(x_7);
 lean_dec(x_6);
 lean_dec(x_5);
 lean_dec(x_4);
-lean_dec(x_3);
 lean_dec(x_2);
 lean_dec(x_1);
 x_68 = lean_alloc_ctor(1, 2, 0);
@@ -2891,7 +2900,6 @@ lean_dec(x_7);
 lean_dec(x_6);
 lean_dec(x_5);
 lean_dec(x_4);
-lean_dec(x_3);
 lean_dec(x_2);
 lean_dec(x_1);
 x_71 = lean_ctor_get(x_70, 0);
@@ -2956,7 +2964,6 @@ lean_dec(x_7);
 lean_dec(x_6);
 lean_dec(x_5);
 lean_dec(x_4);
-lean_dec(x_3);
 lean_dec(x_2);
 lean_dec(x_1);
 if (lean_is_scalar(x_78)) {
@@ -2978,7 +2985,6 @@ lean_dec(x_7);
 lean_dec(x_6);
 lean_dec(x_5);
 lean_dec(x_4);
-lean_dec(x_3);
 lean_dec(x_2);
 lean_dec(x_1);
 if (lean_is_scalar(x_78)) {
@@ -3007,13 +3013,11 @@ lean_inc(x_87);
 lean_dec(x_85);
 lean_inc(x_4);
 lean_inc(x_2);
-lean_inc(x_3);
 x_88 = l___private_Lean_Elab_PreDefinition_Eqns_0__Lean_Elab_Eqns_findMatchToSplit_x3f(x_87, x_3, x_2, x_4);
 if (lean_obj_tag(x_88) == 0)
 {
 lean_object* x_89; lean_object* x_90; lean_object* x_91; lean_object* x_92; lean_object* x_93; lean_object* x_94; uint8_t x_95; 
 lean_dec(x_4);
-lean_dec(x_3);
 lean_dec(x_2);
 x_89 = l_Lean_Elab_Eqns_splitMatch_x3f_go___closed__4;
 x_90 = l_Lean_isTracingEnabledFor___at_Lean_Meta_processPostponed_loop___spec__1(x_89, x_5, x_6, x_7, x_8, x_86);
@@ -3097,7 +3101,6 @@ lean_dec(x_7);
 lean_dec(x_6);
 lean_dec(x_5);
 lean_dec(x_4);
-lean_dec(x_3);
 lean_dec(x_2);
 lean_dec(x_1);
 x_110 = lean_ctor_get(x_109, 0);
@@ -3167,7 +3170,6 @@ lean_dec(x_7);
 lean_dec(x_6);
 lean_dec(x_5);
 lean_dec(x_4);
-lean_dec(x_3);
 lean_dec(x_2);
 lean_dec(x_1);
 if (lean_is_scalar(x_117)) {
@@ -3189,7 +3191,6 @@ lean_dec(x_7);
 lean_dec(x_6);
 lean_dec(x_5);
 lean_dec(x_4);
-lean_dec(x_3);
 lean_dec(x_2);
 lean_dec(x_1);
 if (lean_is_scalar(x_117)) {
@@ -3219,6 +3220,15 @@ lean_dec(x_1);
 return x_7;
 }
 }
+LEAN_EXPORT lean_object* l_Lean_Elab_Eqns_splitMatch_x3f_go___boxed(lean_object* x_1, lean_object* x_2, lean_object* x_3, lean_object* x_4, lean_object* x_5, lean_object* x_6, lean_object* x_7, lean_object* x_8, lean_object* x_9) {
+_start:
+{
+lean_object* x_10; 
+x_10 = l_Lean_Elab_Eqns_splitMatch_x3f_go(x_1, x_2, x_3, x_4, x_5, x_6, x_7, x_8, x_9);
+lean_dec(x_3);
+return x_10;
+}
+}
 static lean_object* _init_l_Lean_Elab_Eqns_splitMatch_x3f___lambda__1___closed__1() {
 _start:
 {
@@ -3248,6 +3258,7 @@ lean_inc(x_10);
 lean_dec(x_8);
 x_11 = l_Lean_Elab_Eqns_splitMatch_x3f___lambda__1___closed__1;
 x_12 = l_Lean_Elab_Eqns_splitMatch_x3f_go(x_1, x_2, x_9, x_11, x_3, x_4, x_5, x_6, x_10);
+lean_dec(x_9);
 return x_12;
 }
 else
@@ -8744,12 +8755,11 @@ lean_object* x_8; lean_object* x_9;
 lean_inc(x_1);
 x_8 = lean_alloc_closure((void*)(l___private_Lean_Elab_PreDefinition_Eqns_0__Lean_Elab_Eqns_saveEqn_isIrrelevant___lambda__1___boxed), 2, 1);
 lean_closure_set(x_8, 0, x_1);
-lean_inc(x_2);
-x_9 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_8, x_2);
+x_9 = lean_find_expr(x_8, x_2);
+lean_dec(x_8);
 if (lean_obj_tag(x_9) == 0)
 {
 uint8_t x_10; lean_object* x_11; lean_object* x_12; 
-lean_dec(x_2);
 lean_dec(x_1);
 x_10 = 1;
 x_11 = lean_box(x_10);
@@ -8768,7 +8778,6 @@ x_15 = l_Lean_Expr_isAppOfArity(x_2, x_13, x_14);
 if (x_15 == 0)
 {
 uint8_t x_16; lean_object* x_17; lean_object* x_18; 
-lean_dec(x_2);
 lean_dec(x_1);
 x_16 = 0;
 x_17 = lean_box(x_16);
@@ -8784,7 +8793,6 @@ x_19 = l_Lean_Expr_appFn_x21(x_2);
 x_20 = l_Lean_Expr_appArg_x21(x_19);
 lean_dec(x_19);
 x_21 = l_Lean_Expr_appArg_x21(x_2);
-lean_dec(x_2);
 x_36 = l_Lean_Expr_isFVar(x_20);
 if (x_36 == 0)
 {
@@ -8894,6 +8902,7 @@ lean_dec(x_6);
 lean_dec(x_5);
 lean_dec(x_4);
 lean_dec(x_3);
+lean_dec(x_2);
 return x_8;
 }
 }
@@ -11724,6 +11733,7 @@ lean_inc(x_54);
 lean_dec(x_52);
 lean_inc(x_39);
 x_55 = l___private_Lean_Elab_PreDefinition_Eqns_0__Lean_Elab_Eqns_saveEqn_isIrrelevant(x_39, x_53, x_8, x_9, x_10, x_11, x_54);
+lean_dec(x_53);
 x_56 = lean_ctor_get(x_55, 0);
 lean_inc(x_56);
 x_57 = lean_unbox(x_56);
@@ -11931,6 +11941,7 @@ lean_inc(x_91);
 lean_dec(x_89);
 lean_inc(x_39);
 x_92 = l___private_Lean_Elab_PreDefinition_Eqns_0__Lean_Elab_Eqns_saveEqn_isIrrelevant(x_39, x_90, x_8, x_9, x_10, x_11, x_91);
+lean_dec(x_90);
 x_93 = lean_ctor_get(x_92, 0);
 lean_inc(x_93);
 x_94 = lean_unbox(x_93);
@@ -12163,6 +12174,7 @@ lean_inc(x_134);
 lean_dec(x_132);
 lean_inc(x_118);
 x_135 = l___private_Lean_Elab_PreDefinition_Eqns_0__Lean_Elab_Eqns_saveEqn_isIrrelevant(x_118, x_133, x_8, x_9, x_10, x_11, x_134);
+lean_dec(x_133);
 x_136 = lean_ctor_get(x_135, 0);
 lean_inc(x_136);
 x_137 = lean_unbox(x_136);
@@ -12426,6 +12438,7 @@ lean_inc(x_182);
 lean_dec(x_180);
 lean_inc(x_164);
 x_183 = l___private_Lean_Elab_PreDefinition_Eqns_0__Lean_Elab_Eqns_saveEqn_isIrrelevant(x_164, x_181, x_8, x_9, x_10, x_11, x_182);
+lean_dec(x_181);
 x_184 = lean_ctor_get(x_183, 0);
 lean_inc(x_184);
 x_185 = lean_unbox(x_184);
@@ -13006,6 +13019,7 @@ lean_inc(x_54);
 lean_dec(x_52);
 lean_inc(x_39);
 x_55 = l___private_Lean_Elab_PreDefinition_Eqns_0__Lean_Elab_Eqns_saveEqn_isIrrelevant(x_39, x_53, x_8, x_9, x_10, x_11, x_54);
+lean_dec(x_53);
 x_56 = lean_ctor_get(x_55, 0);
 lean_inc(x_56);
 x_57 = lean_unbox(x_56);
@@ -13213,6 +13227,7 @@ lean_inc(x_91);
 lean_dec(x_89);
 lean_inc(x_39);
 x_92 = l___private_Lean_Elab_PreDefinition_Eqns_0__Lean_Elab_Eqns_saveEqn_isIrrelevant(x_39, x_90, x_8, x_9, x_10, x_11, x_91);
+lean_dec(x_90);
 x_93 = lean_ctor_get(x_92, 0);
 lean_inc(x_93);
 x_94 = lean_unbox(x_93);
@@ -13445,6 +13460,7 @@ lean_inc(x_134);
 lean_dec(x_132);
 lean_inc(x_118);
 x_135 = l___private_Lean_Elab_PreDefinition_Eqns_0__Lean_Elab_Eqns_saveEqn_isIrrelevant(x_118, x_133, x_8, x_9, x_10, x_11, x_134);
+lean_dec(x_133);
 x_136 = lean_ctor_get(x_135, 0);
 lean_inc(x_136);
 x_137 = lean_unbox(x_136);
@@ -13708,6 +13724,7 @@ lean_inc(x_182);
 lean_dec(x_180);
 lean_inc(x_164);
 x_183 = l___private_Lean_Elab_PreDefinition_Eqns_0__Lean_Elab_Eqns_saveEqn_isIrrelevant(x_164, x_181, x_8, x_9, x_10, x_11, x_182);
+lean_dec(x_181);
 x_184 = lean_ctor_get(x_183, 0);
 lean_inc(x_184);
 x_185 = lean_unbox(x_184);
diff --git a/stage0/stdlib/Lean/Elab/PreDefinition/Main.c b/stage0/stdlib/Lean/Elab/PreDefinition/Main.c
index 5a3b6c8c8e..1b6273462d 100644
--- a/stage0/stdlib/Lean/Elab/PreDefinition/Main.c
+++ b/stage0/stdlib/Lean/Elab/PreDefinition/Main.c
@@ -311,7 +311,6 @@ LEAN_EXPORT lean_object* l_Array_forInUnsafe_loop___at_Lean_Elab_addPreDefinitio
 lean_object* l_Lean_Elab_Term_addTermInfo_x27(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, uint8_t, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 static lean_object* l_Array_mapMUnsafe_map___at___private_Lean_Elab_PreDefinition_Main_0__Lean_Elab_partitionPreDefs___spec__25___closed__1;
 LEAN_EXPORT lean_object* l___private_Lean_Elab_PreDefinition_Main_0__Lean_Elab_partitionPreDefs___lambda__1(lean_object*, lean_object*, size_t, size_t, lean_object*, lean_object*);
-lean_object* l_Lean_Expr_FindImpl_findUnsafe_x3f(lean_object*, lean_object*);
 static lean_object* l_Array_forInUnsafe_loop___at___private_Lean_Elab_PreDefinition_Main_0__Lean_Elab_addAndCompilePartial___spec__2___lambda__3___closed__1;
 static lean_object* l_Lean_throwMaxRecDepthAt___at___private_Lean_Elab_PreDefinition_Main_0__Lean_Elab_betaReduceLetRecApps___spec__9___rarg___closed__2;
 static lean_object* l_Array_forInUnsafe_loop___at_Lean_Elab_checkTerminationByHints___spec__3___lambda__3___closed__3;
@@ -445,6 +444,7 @@ static lean_object* l___private_Lean_Util_SCC_0__Lean_SCC_resetOnStack___at___pr
 lean_object* lean_array_get_size(lean_object*);
 lean_object* l_Lean_Meta_collectMVars(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 lean_object* l_ReaderT_bind___at_Lean_Meta_zetaReduce___spec__14___rarg(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
+lean_object* lean_find_expr(lean_object*, lean_object*);
 static lean_object* l_Lean_Elab_initFn____x40_Lean_Elab_PreDefinition_Main___hyg_3053____closed__6;
 uint8_t lean_nat_dec_le(lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l___private_Lean_Elab_PreDefinition_Main_0__Lean_Elab_addAsAxioms(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
@@ -1431,7 +1431,9 @@ lean_closure_set(x_2, 0, x_1);
 x_3 = lean_ctor_get(x_1, 5);
 lean_inc(x_3);
 lean_dec(x_1);
-x_4 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_2, x_3);
+x_4 = lean_find_expr(x_2, x_3);
+lean_dec(x_3);
+lean_dec(x_2);
 if (lean_obj_tag(x_4) == 0)
 {
 uint8_t x_5; 
diff --git a/stage0/stdlib/Lean/Elab/PreDefinition/Structural/BRecOn.c b/stage0/stdlib/Lean/Elab/PreDefinition/Structural/BRecOn.c
index 48b8ad1fdc..348ac2014f 100644
--- a/stage0/stdlib/Lean/Elab/PreDefinition/Structural/BRecOn.c
+++ b/stage0/stdlib/Lean/Elab/PreDefinition/Structural/BRecOn.c
@@ -21270,7 +21270,6 @@ lean_inc(x_7);
 x_8 = lean_ctor_get(x_6, 2);
 lean_inc(x_8);
 lean_dec(x_6);
-lean_inc(x_1);
 x_9 = l_Lean_Elab_Structural_recArgHasLooseBVarsAt(x_7, x_8, x_1);
 if (x_9 == 0)
 {
@@ -21283,7 +21282,6 @@ goto _start;
 else
 {
 uint8_t x_13; 
-lean_dec(x_1);
 x_13 = 1;
 return x_13;
 }
@@ -21291,7 +21289,6 @@ return x_13;
 else
 {
 uint8_t x_14; 
-lean_dec(x_1);
 x_14 = 0;
 return x_14;
 }
@@ -28464,7 +28461,6 @@ else
 size_t x_40; size_t x_41; uint8_t x_42; 
 x_40 = 0;
 x_41 = lean_usize_of_nat(x_36);
-lean_inc(x_1);
 x_42 = l_Array_anyMUnsafe_any___at___private_Lean_Elab_PreDefinition_Structural_BRecOn_0__Lean_Elab_Structural_replaceRecApps_loop___spec__28(x_1, x_3, x_40, x_41);
 if (x_42 == 0)
 {
@@ -29971,6 +29967,7 @@ x_6 = lean_unbox_usize(x_4);
 lean_dec(x_4);
 x_7 = l_Array_anyMUnsafe_any___at___private_Lean_Elab_PreDefinition_Structural_BRecOn_0__Lean_Elab_Structural_replaceRecApps_loop___spec__28(x_1, x_2, x_5, x_6);
 lean_dec(x_2);
+lean_dec(x_1);
 x_8 = lean_box(x_7);
 return x_8;
 }
diff --git a/stage0/stdlib/Lean/Elab/PreDefinition/Structural/Basic.c b/stage0/stdlib/Lean/Elab/PreDefinition/Structural/Basic.c
index cdbd259521..684ae1a78d 100644
--- a/stage0/stdlib/Lean/Elab/PreDefinition/Structural/Basic.c
+++ b/stage0/stdlib/Lean/Elab/PreDefinition/Structural/Basic.c
@@ -91,7 +91,6 @@ LEAN_EXPORT lean_object* l_Lean_throwError___at_Lean_Elab_Structural_instInhabit
 LEAN_EXPORT lean_object* l_Array_foldlMUnsafe_fold___at_Lean_Elab_Structural_Positions_groupAndSort___spec__1___rarg___boxed(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_panic___at_Lean_Elab_Structural_Positions_mapMwith___spec__1(lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Array_foldlMUnsafe_fold___at_Lean_Elab_Structural_Positions_groupAndSort___spec__1(lean_object*, lean_object*);
-lean_object* l_Lean_Expr_FindImpl_findUnsafe_x3f(lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_panic___at_Lean_Elab_Structural_Positions_groupAndSort___spec__4(lean_object*);
 LEAN_EXPORT uint8_t l_Array_isEqvAux___at_Lean_Elab_Structural_Positions_groupAndSort___spec__5___rarg(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_panic___at_Lean_Elab_Structural_Positions_mapMwith___spec__2(lean_object*, lean_object*);
@@ -124,6 +123,7 @@ LEAN_EXPORT lean_object* l_Array_mapMUnsafe_map___at_Lean_Elab_Structural_Positi
 lean_object* lean_string_append(lean_object*, lean_object*);
 lean_object* lean_array_get_size(lean_object*);
 static lean_object* l_initFn____x40_Lean_Elab_PreDefinition_Structural_Basic___hyg_382____closed__20;
+lean_object* lean_find_expr(lean_object*, lean_object*);
 uint8_t lean_nat_dec_le(lean_object*, lean_object*);
 uint8_t lean_usize_dec_lt(size_t, size_t);
 static lean_object* l_initFn____x40_Lean_Elab_PreDefinition_Structural_Basic___hyg_382____closed__11;
@@ -439,7 +439,8 @@ lean_object* x_4; lean_object* x_5;
 x_4 = lean_alloc_closure((void*)(l_Lean_Elab_Structural_recArgHasLooseBVarsAt___lambda__1___boxed), 3, 2);
 lean_closure_set(x_4, 0, x_1);
 lean_closure_set(x_4, 1, x_2);
-x_5 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_4, x_3);
+x_5 = lean_find_expr(x_4, x_3);
+lean_dec(x_4);
 if (lean_obj_tag(x_5) == 0)
 {
 uint8_t x_6; 
@@ -472,6 +473,7 @@ _start:
 {
 uint8_t x_4; lean_object* x_5; 
 x_4 = l_Lean_Elab_Structural_recArgHasLooseBVarsAt(x_1, x_2, x_3);
+lean_dec(x_3);
 x_5 = lean_box(x_4);
 return x_5;
 }
diff --git a/stage0/stdlib/Lean/Elab/PreDefinition/Structural/IndPred.c b/stage0/stdlib/Lean/Elab/PreDefinition/Structural/IndPred.c
index c316119fef..9580287dad 100644
--- a/stage0/stdlib/Lean/Elab/PreDefinition/Structural/IndPred.c
+++ b/stage0/stdlib/Lean/Elab/PreDefinition/Structural/IndPred.c
@@ -4896,7 +4896,6 @@ x_24 = lean_ctor_get(x_1, 0);
 lean_inc(x_24);
 x_25 = lean_ctor_get(x_1, 2);
 lean_inc(x_25);
-lean_inc(x_4);
 lean_inc(x_24);
 x_26 = l_Lean_Elab_Structural_recArgHasLooseBVarsAt(x_24, x_25, x_4);
 if (x_26 == 0)
diff --git a/stage0/stdlib/Lean/Elab/PreDefinition/Structural/Preprocess.c b/stage0/stdlib/Lean/Elab/PreDefinition/Structural/Preprocess.c
index f6c1930548..28a1520c4e 100644
--- a/stage0/stdlib/Lean/Elab/PreDefinition/Structural/Preprocess.c
+++ b/stage0/stdlib/Lean/Elab/PreDefinition/Structural/Preprocess.c
@@ -40,7 +40,6 @@ lean_object* l___private_Init_Util_0__mkPanicMessageWithDecl(lean_object*, lean_
 LEAN_EXPORT lean_object* l_Lean_Elab_Structural_preprocess___lambda__2(lean_object*, lean_object*, lean_object*, lean_object*);
 static lean_object* l_Lean_Elab_Structural_preprocess___lambda__3___closed__6;
 lean_object* l_Lean_Core_transform___at_Lean_Core_betaReduce___spec__1(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
-lean_object* l_Lean_Expr_FindImpl_findUnsafe_x3f(lean_object*, lean_object*);
 uint8_t l_Array_contains___at_Lean_registerInternalExceptionId___spec__1(lean_object*, lean_object*);
 lean_object* lean_panic_fn(lean_object*, lean_object*);
 lean_object* lean_nat_sub(lean_object*, lean_object*);
@@ -52,6 +51,7 @@ static lean_object* l_Lean_Elab_Structural_preprocess___closed__1;
 LEAN_EXPORT lean_object* l_Lean_Elab_Structural_preprocess___lambda__2___boxed(lean_object*, lean_object*, lean_object*, lean_object*);
 lean_object* l_Lean_Expr_headBeta(lean_object*);
 uint8_t l_Lean_Expr_isMData(lean_object*);
+lean_object* lean_find_expr(lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_Elab_Structural_preprocess___lambda__3(lean_object*, lean_object*, lean_object*, lean_object*);
 uint8_t l_Lean_Expr_isConst(lean_object*);
 lean_object* l_Lean_Expr_beta(lean_object*, lean_object*);
@@ -96,7 +96,9 @@ lean_object* x_6; lean_object* x_7; lean_object* x_8;
 x_6 = lean_alloc_closure((void*)(l___private_Lean_Elab_PreDefinition_Structural_Preprocess_0__Lean_Elab_Structural_shouldBetaReduce___lambda__1___boxed), 2, 1);
 lean_closure_set(x_6, 0, x_2);
 x_7 = l_Lean_Expr_getAppFn(x_1);
-x_8 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_6, x_7);
+x_8 = lean_find_expr(x_6, x_7);
+lean_dec(x_7);
+lean_dec(x_6);
 if (lean_obj_tag(x_8) == 0)
 {
 uint8_t x_9; 
diff --git a/stage0/stdlib/Lean/Elab/PreDefinition/Structural/SmartUnfolding.c b/stage0/stdlib/Lean/Elab/PreDefinition/Structural/SmartUnfolding.c
index 54bceeeb4f..49f6f4ba1d 100644
--- a/stage0/stdlib/Lean/Elab/PreDefinition/Structural/SmartUnfolding.c
+++ b/stage0/stdlib/Lean/Elab/PreDefinition/Structural/SmartUnfolding.c
@@ -86,7 +86,6 @@ static lean_object* l_Array_forInUnsafe_loop___at_Lean_Elab_Structural_addSmartU
 static lean_object* l_Array_forInUnsafe_loop___at_Lean_Elab_Structural_addSmartUnfoldingDefAux_visit___spec__9___lambda__3___closed__6;
 lean_object* l_Array_extract___rarg(lean_object*, lean_object*, lean_object*);
 static lean_object* l_Array_forInUnsafe_loop___at_Lean_Elab_Structural_addSmartUnfoldingDefAux_visit___spec__9___lambda__3___closed__1;
-lean_object* l_Lean_Expr_FindImpl_findUnsafe_x3f(lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_Meta_matchMatcherApp_x3f___at_Lean_Elab_Structural_addSmartUnfoldingDefAux_visit___spec__1___lambda__4___boxed(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_Meta_matchMatcherApp_x3f___at_Lean_Elab_Structural_addSmartUnfoldingDefAux_visit___spec__1___lambda__1(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_Meta_matchMatcherApp_x3f___at_Lean_Elab_Structural_addSmartUnfoldingDefAux_visit___spec__1___lambda__4(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
@@ -122,6 +121,7 @@ lean_object* l___private_Lean_Expr_0__Lean_Expr_getAppArgsAux(lean_object*, lean
 uint8_t l_Lean_isAuxRecursorWithSuffix(lean_object*, lean_object*, lean_object*);
 lean_object* lean_array_get_size(lean_object*);
 LEAN_EXPORT lean_object* l_Array_forInUnsafe_loop___at_Lean_Elab_Structural_addSmartUnfoldingDefAux_visit___spec__9___lambda__3___boxed(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
+lean_object* lean_find_expr(lean_object*, lean_object*);
 uint8_t lean_nat_dec_le(lean_object*, lean_object*);
 uint8_t lean_usize_dec_lt(size_t, size_t);
 lean_object* l_Lean_Meta_mkLambdaFVars(lean_object*, lean_object*, uint8_t, uint8_t, uint8_t, uint8_t, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
@@ -2123,8 +2123,7 @@ x_13 = lean_ctor_get(x_11, 1);
 lean_inc(x_13);
 lean_dec(x_11);
 x_14 = l_Array_forInUnsafe_loop___at_Lean_Elab_Structural_addSmartUnfoldingDefAux_visit___spec__9___lambda__2___closed__1;
-lean_inc(x_12);
-x_15 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_14, x_12);
+x_15 = lean_find_expr(x_14, x_12);
 if (lean_obj_tag(x_15) == 0)
 {
 lean_object* x_16; uint8_t x_17; uint8_t x_18; uint8_t x_19; lean_object* x_20; 
@@ -2944,7 +2943,6 @@ lean_inc(x_21);
 lean_dec(x_11);
 x_22 = lean_ctor_get(x_1, 3);
 lean_inc(x_22);
-lean_inc(x_3);
 lean_inc(x_2);
 x_23 = l_Lean_Elab_Structural_recArgHasLooseBVarsAt(x_22, x_2, x_3);
 if (x_23 == 0)
diff --git a/stage0/stdlib/Lean/Elab/PreDefinition/WF/Preprocess.c b/stage0/stdlib/Lean/Elab/PreDefinition/WF/Preprocess.c
index cd9c5e8171..a85249059d 100644
--- a/stage0/stdlib/Lean/Elab/PreDefinition/WF/Preprocess.c
+++ b/stage0/stdlib/Lean/Elab/PreDefinition/WF/Preprocess.c
@@ -40,7 +40,6 @@ lean_object* l___private_Init_Util_0__mkPanicMessageWithDecl(lean_object*, lean_
 static lean_object* l_Lean_Elab_WF_preprocess___closed__1;
 static lean_object* l_panic___at_Lean_Elab_WF_preprocess___spec__1___closed__1;
 lean_object* l_Lean_Core_transform___at_Lean_Core_betaReduce___spec__1(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
-lean_object* l_Lean_Expr_FindImpl_findUnsafe_x3f(lean_object*, lean_object*);
 uint8_t lean_nat_dec_lt(lean_object*, lean_object*);
 uint8_t l_Lean_Expr_isConstOf(lean_object*, lean_object*);
 lean_object* lean_panic_fn(lean_object*, lean_object*);
@@ -57,6 +56,7 @@ static lean_object* l_Lean_Elab_WF_preprocess___lambda__2___closed__5;
 LEAN_EXPORT uint8_t l___private_Lean_Elab_PreDefinition_WF_Preprocess_0__Lean_Elab_WF_shouldBetaReduce___lambda__1(lean_object*, lean_object*);
 lean_object* lean_array_get_size(lean_object*);
 uint8_t l_Lean_Expr_isMData(lean_object*);
+lean_object* lean_find_expr(lean_object*, lean_object*);
 lean_object* l_Lean_Expr_beta(lean_object*, lean_object*);
 uint8_t l_Lean_KVMap_contains(lean_object*, lean_object*);
 LEAN_EXPORT uint8_t l_Array_anyMUnsafe_any___at___private_Lean_Elab_PreDefinition_WF_Preprocess_0__Lean_Elab_WF_shouldBetaReduce___spec__1(lean_object* x_1, lean_object* x_2, size_t x_3, size_t x_4) {
@@ -137,7 +137,9 @@ lean_object* x_6; lean_object* x_7; lean_object* x_8;
 x_6 = lean_alloc_closure((void*)(l___private_Lean_Elab_PreDefinition_WF_Preprocess_0__Lean_Elab_WF_shouldBetaReduce___lambda__1___boxed), 2, 1);
 lean_closure_set(x_6, 0, x_2);
 x_7 = l_Lean_Expr_getAppFn(x_1);
-x_8 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_6, x_7);
+x_8 = lean_find_expr(x_6, x_7);
+lean_dec(x_7);
+lean_dec(x_6);
 if (lean_obj_tag(x_8) == 0)
 {
 uint8_t x_9; 
diff --git a/stage0/stdlib/Lean/Elab/StructInst.c b/stage0/stdlib/Lean/Elab/StructInst.c
index a621c1c22a..134af703bf 100644
--- a/stage0/stdlib/Lean/Elab/StructInst.c
+++ b/stage0/stdlib/Lean/Elab/StructInst.c
@@ -614,7 +614,6 @@ static lean_object* l_Lean_Elab_Term_StructInst_initFn____x40_Lean_Elab_StructIn
 static lean_object* l_List_foldlM___at___private_Lean_Elab_StructInst_0__Lean_Elab_Term_StructInst_elabStruct___spec__3___lambda__1___closed__1;
 LEAN_EXPORT lean_object* l___private_Lean_Elab_StructInst_0__Lean_Elab_Term_StructInst_isSimpleField_x3f___boxed(lean_object*);
 LEAN_EXPORT lean_object* l_Lean_Elab_Term_StructInst_DefaultFields_step(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
-lean_object* l_Lean_Expr_FindImpl_findUnsafe_x3f(lean_object*, lean_object*);
 static lean_object* l___private_Lean_Elab_StructInst_0__Lean_Elab_Term_StructInst_elabModifyOp___lambda__3___closed__7;
 LEAN_EXPORT lean_object* l_panic___at___private_Lean_Elab_StructInst_0__Lean_Elab_Term_StructInst_getStructSource___spec__1(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_Elab_liftMacroM___at___private_Lean_Elab_StructInst_0__Lean_Elab_Term_StructInst_elabStructInstAux___spec__1___lambda__3(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
@@ -846,6 +845,7 @@ static lean_object* l_List_format___at_Lean_Elab_Term_StructInst_formatStruct___
 LEAN_EXPORT lean_object* l_Lean_Elab_Term_StructInst_formatStruct(lean_object*);
 LEAN_EXPORT lean_object* l___private_Lean_Elab_StructInst_0__Lean_Elab_Term_StructInst_getStructSource(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 lean_object* lean_infer_type(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
+lean_object* lean_find_expr(lean_object*, lean_object*);
 static lean_object* l___private_Lean_Elab_StructInst_0__Lean_Elab_Term_StructInst_elabModifyOp___lambda__3___closed__2;
 static lean_object* l_Array_foldlMUnsafe_fold___at___private_Lean_Elab_StructInst_0__Lean_Elab_Term_StructInst_isModifyOp_x3f___spec__3___closed__6;
 LEAN_EXPORT lean_object* l_Array_forInUnsafe_loop___at_Lean_Elab_Term_StructInst_DefaultFields_mkDefaultValueAux_x3f___spec__1(lean_object*, lean_object*, lean_object*, size_t, size_t, lean_object*);
@@ -29073,8 +29073,7 @@ x_69 = lean_ctor_get(x_67, 1);
 lean_inc(x_69);
 lean_dec(x_67);
 x_70 = l_Lean_Elab_Term_StructInst_DefaultFields_tryToSynthesizeDefault_loop___closed__1;
-lean_inc(x_68);
-x_71 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_70, x_68);
+x_71 = lean_find_expr(x_70, x_68);
 if (lean_obj_tag(x_71) == 0)
 {
 lean_object* x_72; lean_object* x_73; lean_object* x_74; lean_object* x_75; lean_object* x_76; lean_object* x_77; 
@@ -29295,8 +29294,7 @@ x_122 = lean_ctor_get(x_120, 1);
 lean_inc(x_122);
 lean_dec(x_120);
 x_123 = l_Lean_Elab_Term_StructInst_DefaultFields_tryToSynthesizeDefault_loop___closed__1;
-lean_inc(x_121);
-x_124 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_123, x_121);
+x_124 = lean_find_expr(x_123, x_121);
 if (lean_obj_tag(x_124) == 0)
 {
 lean_object* x_125; lean_object* x_126; lean_object* x_127; lean_object* x_128; lean_object* x_129; lean_object* x_130; lean_object* x_131; 
diff --git a/stage0/stdlib/Lean/Elab/Tactic/LibrarySearch.c b/stage0/stdlib/Lean/Elab/Tactic/LibrarySearch.c
index 3bc701981b..e8a52cbe65 100644
--- a/stage0/stdlib/Lean/Elab/Tactic/LibrarySearch.c
+++ b/stage0/stdlib/Lean/Elab/Tactic/LibrarySearch.c
@@ -1206,6 +1206,7 @@ _start:
 {
 uint8_t x_3; lean_object* x_4; 
 x_3 = l_Lean_Elab_LibrarySearch_exact_x3f___lambda__2(x_1, x_2);
+lean_dec(x_1);
 x_4 = lean_box(x_3);
 return x_4;
 }
diff --git a/stage0/stdlib/Lean/Elab/Term.c b/stage0/stdlib/Lean/Elab/Term.c
index 2db0a3d4ff..be13f2a2a9 100644
--- a/stage0/stdlib/Lean/Elab/Term.c
+++ b/stage0/stdlib/Lean/Elab/Term.c
@@ -54993,6 +54993,7 @@ x_29 = lean_ctor_get(x_27, 1);
 lean_inc(x_29);
 lean_dec(x_27);
 x_30 = l_Lean_Expr_hasSyntheticSorry(x_28);
+lean_dec(x_28);
 if (x_30 == 0)
 {
 lean_object* x_31; lean_object* x_32; 
diff --git a/stage0/stdlib/Lean/Environment.c b/stage0/stdlib/Lean/Environment.c
index d1f4be17e3..57083d5ee2 100644
--- a/stage0/stdlib/Lean/Environment.c
+++ b/stage0/stdlib/Lean/Environment.c
@@ -494,7 +494,6 @@ LEAN_EXPORT uint8_t l_Lean_Environment_getModuleIdx_x3f___lambda__1(lean_object*
 LEAN_EXPORT lean_object* l_Lean_mkModuleData___lambda__2(lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_Kernel_instInhabitedDiagnostics;
 LEAN_EXPORT lean_object* l___private_Lean_Environment_0__Lean_EnvExtensionInterfaceUnsafe_invalidExtMsg;
-lean_object* l_Lean_Expr_FindImpl_findUnsafe_x3f(lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_EnvExtensionInterfaceUnsafe_imp;
 LEAN_EXPORT lean_object* l_Lean_Environment_hasUnsafe___lambda__1___boxed(lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Array_foldlMUnsafe_fold___at_Lean_Environment_displayStats___spec__6___lambda__1(lean_object*, lean_object*, lean_object*);
@@ -732,6 +731,7 @@ LEAN_EXPORT lean_object* l_Lean_mkHashMap___at_Lean_mkExtNameMap___spec__1___box
 static lean_object* l_Lean_Environment_displayStats___closed__2;
 LEAN_EXPORT lean_object* l_Lean_saveModuleData___boxed(lean_object*, lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_instMonadEnvOfMonadLift___rarg(lean_object*, lean_object*);
+lean_object* lean_find_expr(lean_object*, lean_object*);
 uint8_t lean_nat_dec_le(lean_object*, lean_object*);
 lean_object* l_Lean_SMap_insert___at_Lean_NameSSet_insert___spec__1(lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_PersistentHashMap_insertAtCollisionNodeAux___at_Lean_Kernel_Diagnostics_recordUnfold___spec__7(lean_object*, lean_object*, lean_object*, lean_object*);
@@ -17368,7 +17368,8 @@ _start:
 lean_object* x_3; lean_object* x_4; 
 x_3 = lean_alloc_closure((void*)(l_Lean_Environment_hasUnsafe___lambda__1___boxed), 2, 1);
 lean_closure_set(x_3, 0, x_1);
-x_4 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_3, x_2);
+x_4 = lean_find_expr(x_3, x_2);
+lean_dec(x_3);
 if (lean_obj_tag(x_4) == 0)
 {
 uint8_t x_5; 
@@ -17398,6 +17399,7 @@ _start:
 {
 uint8_t x_3; lean_object* x_4; 
 x_3 = l_Lean_Environment_hasUnsafe(x_1, x_2);
+lean_dec(x_2);
 x_4 = lean_box(x_3);
 return x_4;
 }
@@ -17492,7 +17494,6 @@ LEAN_EXPORT lean_object* l_Lean_mkDefinitionValInferrringUnsafe___rarg___lambda_
 _start:
 {
 uint8_t x_8; lean_object* x_9; lean_object* x_10; lean_object* x_11; lean_object* x_12; lean_object* x_13; 
-lean_inc(x_1);
 lean_inc(x_7);
 x_8 = l_Lean_Environment_hasUnsafe(x_7, x_1);
 x_9 = lean_ctor_get(x_2, 0);
@@ -17513,7 +17514,6 @@ lean_ctor_set(x_13, 1, x_12);
 if (x_8 == 0)
 {
 uint8_t x_14; 
-lean_inc(x_5);
 x_14 = l_Lean_Environment_hasUnsafe(x_7, x_5);
 if (x_14 == 0)
 {
diff --git a/stage0/stdlib/Lean/Message.c b/stage0/stdlib/Lean/Message.c
index eebeeb2f12..707c0e897e 100644
--- a/stage0/stdlib/Lean/Message.c
+++ b/stage0/stdlib/Lean/Message.c
@@ -1855,6 +1855,7 @@ x_4 = lean_ctor_get(x_3, 0);
 lean_inc(x_4);
 lean_dec(x_3);
 x_5 = l_Lean_Expr_hasSyntheticSorry(x_4);
+lean_dec(x_4);
 return x_5;
 }
 }
diff --git a/stage0/stdlib/Lean/Meta/Closure.c b/stage0/stdlib/Lean/Meta/Closure.c
index cf11550b1b..3f1f086a41 100644
--- a/stage0/stdlib/Lean/Meta/Closure.c
+++ b/stage0/stdlib/Lean/Meta/Closure.c
@@ -11563,7 +11563,6 @@ x_13 = lean_ctor_get(x_11, 0);
 x_14 = lean_ctor_get(x_13, 0);
 lean_inc(x_14);
 lean_dec(x_13);
-lean_inc(x_3);
 lean_inc(x_14);
 x_15 = l_Lean_Environment_hasUnsafe(x_14, x_3);
 lean_inc(x_1);
@@ -11578,7 +11577,6 @@ lean_ctor_set(x_18, 1, x_17);
 if (x_15 == 0)
 {
 uint8_t x_19; 
-lean_inc(x_4);
 x_19 = l_Lean_Environment_hasUnsafe(x_14, x_4);
 if (x_19 == 0)
 {
@@ -11633,7 +11631,6 @@ lean_dec(x_11);
 x_28 = lean_ctor_get(x_26, 0);
 lean_inc(x_28);
 lean_dec(x_26);
-lean_inc(x_3);
 lean_inc(x_28);
 x_29 = l_Lean_Environment_hasUnsafe(x_28, x_3);
 lean_inc(x_1);
@@ -11648,7 +11645,6 @@ lean_ctor_set(x_32, 1, x_31);
 if (x_29 == 0)
 {
 uint8_t x_33; 
-lean_inc(x_4);
 x_33 = l_Lean_Environment_hasUnsafe(x_28, x_4);
 if (x_33 == 0)
 {
@@ -12031,7 +12027,6 @@ lean_inc(x_17);
 lean_dec(x_15);
 x_18 = lean_ctor_get(x_11, 1);
 lean_inc(x_18);
-lean_inc(x_18);
 lean_inc(x_17);
 x_19 = l_Lean_Environment_hasUnsafe(x_17, x_18);
 if (x_19 == 0)
@@ -12039,7 +12034,6 @@ if (x_19 == 0)
 lean_object* x_20; uint8_t x_21; 
 x_20 = lean_ctor_get(x_11, 2);
 lean_inc(x_20);
-lean_inc(x_20);
 x_21 = l_Lean_Environment_hasUnsafe(x_17, x_20);
 if (x_21 == 0)
 {
@@ -12337,7 +12331,6 @@ lean_inc(x_104);
 lean_dec(x_102);
 x_105 = lean_ctor_get(x_11, 1);
 lean_inc(x_105);
-lean_inc(x_105);
 lean_inc(x_104);
 x_106 = l_Lean_Environment_hasUnsafe(x_104, x_105);
 if (x_106 == 0)
@@ -12345,7 +12338,6 @@ if (x_106 == 0)
 lean_object* x_107; uint8_t x_108; 
 x_107 = lean_ctor_get(x_11, 2);
 lean_inc(x_107);
-lean_inc(x_107);
 x_108 = l_Lean_Environment_hasUnsafe(x_104, x_107);
 if (x_108 == 0)
 {
diff --git a/stage0/stdlib/Lean/Meta/Constructions/BRecOn.c b/stage0/stdlib/Lean/Meta/Constructions/BRecOn.c
index 630f77b4df..e9277b38a1 100644
--- a/stage0/stdlib/Lean/Meta/Constructions/BRecOn.c
+++ b/stage0/stdlib/Lean/Meta/Constructions/BRecOn.c
@@ -2932,7 +2932,6 @@ x_13 = lean_ctor_get(x_11, 0);
 x_14 = lean_ctor_get(x_13, 0);
 lean_inc(x_14);
 lean_dec(x_13);
-lean_inc(x_3);
 lean_inc(x_14);
 x_15 = l_Lean_Environment_hasUnsafe(x_14, x_3);
 lean_inc(x_1);
@@ -2947,7 +2946,6 @@ lean_ctor_set(x_18, 1, x_17);
 if (x_15 == 0)
 {
 uint8_t x_19; 
-lean_inc(x_4);
 x_19 = l_Lean_Environment_hasUnsafe(x_14, x_4);
 if (x_19 == 0)
 {
@@ -3002,7 +3000,6 @@ lean_dec(x_11);
 x_28 = lean_ctor_get(x_26, 0);
 lean_inc(x_28);
 lean_dec(x_26);
-lean_inc(x_3);
 lean_inc(x_28);
 x_29 = l_Lean_Environment_hasUnsafe(x_28, x_3);
 lean_inc(x_1);
@@ -3017,7 +3014,6 @@ lean_ctor_set(x_32, 1, x_31);
 if (x_29 == 0)
 {
 uint8_t x_33; 
-lean_inc(x_4);
 x_33 = l_Lean_Environment_hasUnsafe(x_28, x_4);
 if (x_33 == 0)
 {
diff --git a/stage0/stdlib/Lean/Meta/Constructions/RecOn.c b/stage0/stdlib/Lean/Meta/Constructions/RecOn.c
index b4bb4a27fa..bb4d77d8d5 100644
--- a/stage0/stdlib/Lean/Meta/Constructions/RecOn.c
+++ b/stage0/stdlib/Lean/Meta/Constructions/RecOn.c
@@ -116,7 +116,6 @@ x_13 = lean_ctor_get(x_11, 0);
 x_14 = lean_ctor_get(x_13, 0);
 lean_inc(x_14);
 lean_dec(x_13);
-lean_inc(x_3);
 lean_inc(x_14);
 x_15 = l_Lean_Environment_hasUnsafe(x_14, x_3);
 lean_inc(x_1);
@@ -131,7 +130,6 @@ lean_ctor_set(x_18, 1, x_17);
 if (x_15 == 0)
 {
 uint8_t x_19; 
-lean_inc(x_4);
 x_19 = l_Lean_Environment_hasUnsafe(x_14, x_4);
 if (x_19 == 0)
 {
@@ -186,7 +184,6 @@ lean_dec(x_11);
 x_28 = lean_ctor_get(x_26, 0);
 lean_inc(x_28);
 lean_dec(x_26);
-lean_inc(x_3);
 lean_inc(x_28);
 x_29 = l_Lean_Environment_hasUnsafe(x_28, x_3);
 lean_inc(x_1);
@@ -201,7 +198,6 @@ lean_ctor_set(x_32, 1, x_31);
 if (x_29 == 0)
 {
 uint8_t x_33; 
-lean_inc(x_4);
 x_33 = l_Lean_Environment_hasUnsafe(x_28, x_4);
 if (x_33 == 0)
 {
diff --git a/stage0/stdlib/Lean/Meta/ExprDefEq.c b/stage0/stdlib/Lean/Meta/ExprDefEq.c
index 8aea3bef0d..23a4d4eadd 100644
--- a/stage0/stdlib/Lean/Meta/ExprDefEq.c
+++ b/stage0/stdlib/Lean/Meta/ExprDefEq.c
@@ -200,10 +200,10 @@ uint8_t l_Array_contains___at___private_Lean_Class_0__Lean_checkOutParam___spec_
 static lean_object* l___private_Lean_Meta_ExprDefEq_0__Lean_Meta_isDefEqQuickOther___lambda__2___closed__3;
 LEAN_EXPORT lean_object* l___private_Lean_Meta_ExprDefEq_0__Lean_Meta_isDefEqLeftRight(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 lean_object* l_Lean_instMonadQuotationOfMonadFunctorOfMonadLift___rarg(lean_object*, lean_object*, lean_object*);
-uint8_t l_Lean_HashSetImp_contains___at_Lean_Expr_FindImpl_checkVisited___spec__8(lean_object*, lean_object*);
 lean_object* l_Lean_Expr_mdata___override(lean_object*, lean_object*);
 LEAN_EXPORT uint8_t l_Array_anyMUnsafe_any___at_Lean_Meta_CheckAssignment_checkMVar___spec__19(lean_object*, lean_object*, size_t, size_t);
 LEAN_EXPORT lean_object* l_Lean_Meta_isDefEqStringLit(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
+LEAN_EXPORT lean_object* l_List_replace___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheckImp_alreadyVisited___spec__8___boxed(lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Array_anyMUnsafe_any___at_Lean_Meta_checkAssignment___spec__7___boxed(lean_object*, lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l___private_Lean_Meta_ExprDefEq_0__Lean_Meta_withProofIrrelTransparency(lean_object*);
 lean_object* l_Lean_exceptBoolEmoji___rarg(lean_object*);
@@ -220,6 +220,7 @@ LEAN_EXPORT lean_object* l___private_Lean_Meta_ExprDefEq_0__Lean_Meta_isDefEqPro
 LEAN_EXPORT lean_object* l___private_Lean_Meta_ExprDefEq_0__Lean_Meta_expandDelayedAssigned_x3f___lambda__2___boxed(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_LocalContext_foldlM___at_Lean_Meta_CheckAssignment_checkMVar___spec__52___boxed(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_Meta_checkpointDefEq___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_isDefEqApp___spec__2(lean_object*, lean_object*, lean_object*, lean_object*, uint8_t, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
+LEAN_EXPORT lean_object* l_List_replace___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheckImp_alreadyVisited___spec__8(lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l___private_Lean_Meta_ExprDefEq_0__Lean_Meta_isAssignable(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l___private_Lean_Meta_ExprDefEq_0__Lean_Meta_isDefEqQuickOther___lambda__2___boxed(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 lean_object* l_Lean_Expr_proj___override(lean_object*, lean_object*, lean_object*);
@@ -437,6 +438,7 @@ lean_object* l_ReaderT_instMonadFunctor(lean_object*, lean_object*, lean_object*
 static lean_object* l_Array_forInUnsafe_loop___at_Lean_Meta_checkAssignment___spec__6___closed__1;
 LEAN_EXPORT lean_object* l___private_Lean_Meta_ExprDefEq_0__Lean_Meta_isDefEqQuickMVarMVar(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 lean_object* l_Lean_instantiateMVars___at___private_Lean_MetavarContext_0__Lean_DependsOn_dep_visitMain___spec__7(lean_object*, lean_object*);
+uint64_t lean_usize_to_uint64(size_t);
 LEAN_EXPORT lean_object* l___private_Lean_Meta_ExprDefEq_0__Lean_Meta_isDefEqProjDelta_tryReduceProjs___boxed(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_getExprMVarAssignment_x3f___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheckImp_occursCheck___spec__4___boxed(lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT uint8_t l_Array_anyMUnsafe_any___at_Lean_Meta_CheckAssignment_checkMVar___spec__27(lean_object*, lean_object*, size_t, size_t);
@@ -509,6 +511,7 @@ LEAN_EXPORT lean_object* l___private_Lean_Meta_ExprDefEq_0__Lean_Meta_unfoldNonP
 LEAN_EXPORT lean_object* l_Lean_Meta_DefEqCache_update___boxed(lean_object*, lean_object*, lean_object*, lean_object*);
 lean_object* l_Lean_Expr_forallE___override(lean_object*, lean_object*, lean_object*, uint8_t);
 lean_object* l_outOfBounds___rarg(lean_object*);
+LEAN_EXPORT lean_object* l_Lean_HashSetImp_contains___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheckImp_alreadyVisited___spec__1___boxed(lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_Meta_CheckAssignment_initFn____x40_Lean_Meta_ExprDefEq___hyg_5827_(lean_object*);
 LEAN_EXPORT lean_object* l___private_Lean_MetavarContext_0__Lean_DependsOn_dep_visit___at_Lean_Meta_CheckAssignment_checkMVar___spec__12___boxed(lean_object*, lean_object*, lean_object*);
 static lean_object* l_Lean_Meta_initFn____x40_Lean_Meta_ExprDefEq___hyg_6____closed__10;
@@ -662,6 +665,7 @@ LEAN_EXPORT lean_object* l_Lean_AssocList_find_x3f___at___private_Lean_Meta_Expr
 LEAN_EXPORT lean_object* l_Lean_occursCheck_visit___at_Lean_Meta_CheckAssignment_checkMVar___spec__69(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 extern lean_object* l_Lean_Meta_instMonadMetaM;
 LEAN_EXPORT lean_object* l___private_Lean_Meta_ExprDefEq_0__Lean_Meta_unstuckMVar___lambda__1(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
+LEAN_EXPORT lean_object* l_Lean_HashSetImp_expand___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheckImp_alreadyVisited___spec__4(lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_withTraceNodeBefore___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_checkTypesAndAssign___spec__1___lambda__3___boxed(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Std_Range_forIn_loop___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_isDefEqEtaStruct_go___spec__1___lambda__1(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l___private_Lean_Meta_ExprDefEq_0__Lean_Meta_isDefEqUnitLike(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
@@ -746,6 +750,7 @@ static lean_object* l___private_Lean_Meta_ExprDefEq_0__Lean_Meta_assignConst___l
 LEAN_EXPORT uint8_t l_Array_anyMUnsafe_any___at_Lean_Meta_CheckAssignment_checkMVar___spec__18(lean_object*, lean_object*, size_t, size_t);
 static lean_object* l_Lean_Meta_initFn____x40_Lean_Meta_ExprDefEq___hyg_48____closed__1;
 LEAN_EXPORT uint8_t l_List_elem___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_mkLambdaFVarsWithLetDeps_collectLetDeclsFrom_visit___spec__10(lean_object*, lean_object*);
+LEAN_EXPORT lean_object* l_List_foldl___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheckImp_alreadyVisited___spec__6___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheckImp_alreadyVisited___spec__7(lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_PersistentHashMap_insertAux___at_Lean_Meta_DefEqCache_update___spec__2(lean_object*, size_t, size_t, lean_object*, uint8_t);
 LEAN_EXPORT lean_object* l___private_Lean_Meta_ExprDefEq_0__Lean_Meta_isDefEqProj_isDefEqSingleton___lambda__3___boxed(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l___private_Lean_Meta_ExprDefEq_0__Lean_Meta_isDefEqArgsFirstPass(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
@@ -821,7 +826,6 @@ LEAN_EXPORT uint8_t l___private_Lean_Meta_ExprDefEq_0__Lean_Meta_etaEq(lean_obje
 LEAN_EXPORT lean_object* l___private_Lean_Meta_ExprDefEq_0__Lean_Meta_unfoldNonProjFnDefEq(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 static lean_object* l_Lean_Meta_isExprDefEqAuxImpl___lambda__3___closed__12;
 lean_object* l_Lean_PersistentHashMap_mkEmptyEntries(lean_object*, lean_object*);
-lean_object* l_Lean_HashSetImp_insert___at_Lean_Expr_FindImpl_checkVisited___spec__1(lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Std_Range_forIn_loop___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_isDefEqArgsFirstPass___spec__1___lambda__3(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_PersistentArray_anyMAux___at_Lean_Meta_CheckAssignment_checkMVar___spec__48___boxed(lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_PersistentHashMap_find_x3f___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_getCachedResult___spec__1___boxed(lean_object*, lean_object*);
@@ -871,6 +875,7 @@ LEAN_EXPORT lean_object* l___private_Lean_Meta_ExprDefEq_0__Lean_Meta_isDefEqPro
 lean_object* lean_nat_sub(lean_object*, lean_object*);
 lean_object* l_Lean_Option_register___at_Lean_initFn____x40_Lean_Util_Profile___hyg_6____spec__1(lean_object*, lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_Meta_CheckAssignment_checkMVar___lambda__1___boxed(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
+LEAN_EXPORT lean_object* l_List_foldl___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheckImp_alreadyVisited___spec__6(lean_object*, lean_object*, lean_object*);
 lean_object* l_Lean_Expr_getAppFn(lean_object*);
 LEAN_EXPORT lean_object* lean_is_expr_def_eq(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l___private_Lean_Meta_ExprDefEq_0__Lean_Meta_isAssignable___boxed(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
@@ -1054,7 +1059,9 @@ uint8_t l_Lean_Exception_isRuntime(lean_object*);
 lean_object* l_Lean_Expr_lam___override(lean_object*, lean_object*, lean_object*, uint8_t);
 static lean_object* l___private_Lean_Meta_ExprDefEq_0__Lean_Meta_unstuckMVar___closed__16;
 lean_object* l_instMonadLiftTOfMonadLift___rarg(lean_object*, lean_object*, lean_object*, lean_object*);
+LEAN_EXPORT lean_object* l_Lean_HashSetImp_moveEntries___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheckImp_alreadyVisited___spec__5(lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Array_foldlMUnsafe_fold___at_Lean_Meta_CheckAssignment_checkMVar___spec__67___boxed(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
+LEAN_EXPORT uint8_t l_List_elem___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheckImp_alreadyVisited___spec__2(lean_object*, lean_object*);
 uint8_t l_Lean_Expr_isFVar(lean_object*);
 LEAN_EXPORT lean_object* l___private_Lean_Meta_ExprDefEq_0__Lean_Meta_isDefEqProjInst___lambda__1___boxed(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Array_anyMUnsafe_any___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_processConstApprox_go___spec__1___boxed(lean_object*, lean_object*, lean_object*, lean_object*);
@@ -1063,6 +1070,7 @@ LEAN_EXPORT uint8_t l___private_Lean_Meta_ExprDefEq_0__Lean_Meta_sameHeadSymbol(
 LEAN_EXPORT lean_object* l___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheck_unsafe__1(lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_Meta_CheckAssignment_checkMVar___lambda__5(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 lean_object* l_Lean_Expr_mvarId_x21(lean_object*);
+LEAN_EXPORT lean_object* l_List_elem___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheckImp_alreadyVisited___spec__2___boxed(lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_Meta_isEtaUnassignedMVar(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 uint8_t lean_is_class(lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_Meta_checkpointDefEq___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_isDefEqApp___spec__2___boxed(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
@@ -1077,6 +1085,7 @@ lean_object* lean_array_uset(lean_object*, size_t, lean_object*);
 LEAN_EXPORT lean_object* l___private_Lean_Meta_ExprDefEq_0__Lean_Meta_expandDelayedAssigned_x3f___boxed(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l___private_Lean_Meta_ExprDefEq_0__Lean_Meta_isDefEqLeft___lambda__1(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 lean_object* l_Lean_MessageData_ofName(lean_object*);
+LEAN_EXPORT lean_object* l_Lean_HashSetImp_insert___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheckImp_alreadyVisited___spec__3(lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l___private_Lean_Meta_ExprDefEq_0__Lean_Meta_isDefEqArgs___boxed(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_isProjectionFn___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_isNonTrivialRegular___spec__1(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 lean_object* lean_array_get(lean_object*, lean_object*, lean_object*);
@@ -1086,6 +1095,7 @@ LEAN_EXPORT lean_object* l___private_Lean_Meta_ExprDefEq_0__Lean_Meta_isDefEqPro
 LEAN_EXPORT lean_object* l_Lean_mkHashSet___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_mkLambdaFVarsWithLetDeps_collectLetDeps___spec__1(lean_object*);
 lean_object* l_Lean_Meta_getPostponed___rarg(lean_object*, lean_object*, lean_object*, lean_object*);
 lean_object* l___private_Lean_Meta_Basic_0__Lean_Meta_instantiateForallAux(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
+LEAN_EXPORT uint8_t l_Lean_HashSetImp_contains___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheckImp_alreadyVisited___spec__1(lean_object*, lean_object*);
 static lean_object* l_Lean_occursCheck_visitMVar___at_Lean_Meta_CheckAssignment_checkMVar___spec__70___closed__1;
 static lean_object* l_Lean_Meta_isExprDefEqAuxImpl___lambda__3___closed__3;
 LEAN_EXPORT lean_object* l___private_Lean_Meta_ExprDefEq_0__Lean_Meta_processAssignmentFOApprox(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
@@ -43528,15 +43538,414 @@ return x_1;
 }
 }
 }
+LEAN_EXPORT uint8_t l_List_elem___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheckImp_alreadyVisited___spec__2(lean_object* x_1, lean_object* x_2) {
+_start:
+{
+if (lean_obj_tag(x_2) == 0)
+{
+uint8_t x_3; 
+x_3 = 0;
+return x_3;
+}
+else
+{
+lean_object* x_4; lean_object* x_5; size_t x_6; size_t x_7; uint8_t x_8; 
+x_4 = lean_ctor_get(x_2, 0);
+x_5 = lean_ctor_get(x_2, 1);
+x_6 = lean_ptr_addr(x_1);
+x_7 = lean_ptr_addr(x_4);
+x_8 = lean_usize_dec_eq(x_6, x_7);
+if (x_8 == 0)
+{
+x_2 = x_5;
+goto _start;
+}
+else
+{
+uint8_t x_10; 
+x_10 = 1;
+return x_10;
+}
+}
+}
+}
+LEAN_EXPORT uint8_t l_Lean_HashSetImp_contains___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheckImp_alreadyVisited___spec__1(lean_object* x_1, lean_object* x_2) {
+_start:
+{
+lean_object* x_3; lean_object* x_4; size_t x_5; uint64_t x_6; uint64_t x_7; uint64_t x_8; size_t x_9; lean_object* x_10; uint8_t x_11; 
+x_3 = lean_ctor_get(x_1, 1);
+x_4 = lean_array_get_size(x_3);
+x_5 = lean_ptr_addr(x_2);
+x_6 = lean_usize_to_uint64(x_5);
+x_7 = 11;
+x_8 = lean_uint64_mix_hash(x_6, x_7);
+x_9 = lean_hashset_mk_idx(x_4, x_8);
+x_10 = lean_array_uget(x_3, x_9);
+x_11 = l_List_elem___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheckImp_alreadyVisited___spec__2(x_2, x_10);
+lean_dec(x_10);
+return x_11;
+}
+}
+LEAN_EXPORT lean_object* l_List_foldl___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheckImp_alreadyVisited___spec__6(lean_object* x_1, lean_object* x_2, lean_object* x_3) {
+_start:
+{
+if (lean_obj_tag(x_3) == 0)
+{
+lean_dec(x_1);
+return x_2;
+}
+else
+{
+uint8_t x_4; 
+x_4 = !lean_is_exclusive(x_3);
+if (x_4 == 0)
+{
+lean_object* x_5; lean_object* x_6; lean_object* x_7; lean_object* x_8; uint64_t x_9; size_t x_10; lean_object* x_11; lean_object* x_12; 
+x_5 = lean_ctor_get(x_3, 0);
+x_6 = lean_ctor_get(x_3, 1);
+x_7 = lean_array_get_size(x_2);
+lean_inc(x_1);
+lean_inc(x_5);
+x_8 = lean_apply_1(x_1, x_5);
+x_9 = lean_unbox_uint64(x_8);
+lean_dec(x_8);
+x_10 = lean_hashset_mk_idx(x_7, x_9);
+x_11 = lean_array_uget(x_2, x_10);
+lean_ctor_set(x_3, 1, x_11);
+x_12 = lean_array_uset(x_2, x_10, x_3);
+x_2 = x_12;
+x_3 = x_6;
+goto _start;
+}
+else
+{
+lean_object* x_14; lean_object* x_15; lean_object* x_16; lean_object* x_17; uint64_t x_18; size_t x_19; lean_object* x_20; lean_object* x_21; lean_object* x_22; 
+x_14 = lean_ctor_get(x_3, 0);
+x_15 = lean_ctor_get(x_3, 1);
+lean_inc(x_15);
+lean_inc(x_14);
+lean_dec(x_3);
+x_16 = lean_array_get_size(x_2);
+lean_inc(x_1);
+lean_inc(x_14);
+x_17 = lean_apply_1(x_1, x_14);
+x_18 = lean_unbox_uint64(x_17);
+lean_dec(x_17);
+x_19 = lean_hashset_mk_idx(x_16, x_18);
+x_20 = lean_array_uget(x_2, x_19);
+x_21 = lean_alloc_ctor(1, 2, 0);
+lean_ctor_set(x_21, 0, x_14);
+lean_ctor_set(x_21, 1, x_20);
+x_22 = lean_array_uset(x_2, x_19, x_21);
+x_2 = x_22;
+x_3 = x_15;
+goto _start;
+}
+}
+}
+}
+LEAN_EXPORT lean_object* l_List_foldl___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheckImp_alreadyVisited___spec__6___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheckImp_alreadyVisited___spec__7(lean_object* x_1, lean_object* x_2) {
+_start:
+{
+if (lean_obj_tag(x_2) == 0)
+{
+return x_1;
+}
+else
+{
+uint8_t x_3; 
+x_3 = !lean_is_exclusive(x_2);
+if (x_3 == 0)
+{
+lean_object* x_4; lean_object* x_5; lean_object* x_6; size_t x_7; uint64_t x_8; uint64_t x_9; uint64_t x_10; size_t x_11; lean_object* x_12; lean_object* x_13; 
+x_4 = lean_ctor_get(x_2, 0);
+x_5 = lean_ctor_get(x_2, 1);
+x_6 = lean_array_get_size(x_1);
+x_7 = lean_ptr_addr(x_4);
+x_8 = lean_usize_to_uint64(x_7);
+x_9 = 11;
+x_10 = lean_uint64_mix_hash(x_8, x_9);
+x_11 = lean_hashset_mk_idx(x_6, x_10);
+x_12 = lean_array_uget(x_1, x_11);
+lean_ctor_set(x_2, 1, x_12);
+x_13 = lean_array_uset(x_1, x_11, x_2);
+x_1 = x_13;
+x_2 = x_5;
+goto _start;
+}
+else
+{
+lean_object* x_15; lean_object* x_16; lean_object* x_17; size_t x_18; uint64_t x_19; uint64_t x_20; uint64_t x_21; size_t x_22; lean_object* x_23; lean_object* x_24; lean_object* x_25; 
+x_15 = lean_ctor_get(x_2, 0);
+x_16 = lean_ctor_get(x_2, 1);
+lean_inc(x_16);
+lean_inc(x_15);
+lean_dec(x_2);
+x_17 = lean_array_get_size(x_1);
+x_18 = lean_ptr_addr(x_15);
+x_19 = lean_usize_to_uint64(x_18);
+x_20 = 11;
+x_21 = lean_uint64_mix_hash(x_19, x_20);
+x_22 = lean_hashset_mk_idx(x_17, x_21);
+x_23 = lean_array_uget(x_1, x_22);
+x_24 = lean_alloc_ctor(1, 2, 0);
+lean_ctor_set(x_24, 0, x_15);
+lean_ctor_set(x_24, 1, x_23);
+x_25 = lean_array_uset(x_1, x_22, x_24);
+x_1 = x_25;
+x_2 = x_16;
+goto _start;
+}
+}
+}
+}
+LEAN_EXPORT lean_object* l_Lean_HashSetImp_moveEntries___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheckImp_alreadyVisited___spec__5(lean_object* x_1, lean_object* x_2, lean_object* x_3) {
+_start:
+{
+lean_object* x_4; uint8_t x_5; 
+x_4 = lean_array_get_size(x_2);
+x_5 = lean_nat_dec_lt(x_1, x_4);
+lean_dec(x_4);
+if (x_5 == 0)
+{
+lean_dec(x_2);
+lean_dec(x_1);
+return x_3;
+}
+else
+{
+lean_object* x_6; lean_object* x_7; lean_object* x_8; lean_object* x_9; lean_object* x_10; lean_object* x_11; 
+x_6 = lean_array_fget(x_2, x_1);
+x_7 = lean_box(0);
+x_8 = lean_array_fset(x_2, x_1, x_7);
+x_9 = l_List_foldl___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheckImp_alreadyVisited___spec__6___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheckImp_alreadyVisited___spec__7(x_3, x_6);
+x_10 = lean_unsigned_to_nat(1u);
+x_11 = lean_nat_add(x_1, x_10);
+lean_dec(x_1);
+x_1 = x_11;
+x_2 = x_8;
+x_3 = x_9;
+goto _start;
+}
+}
+}
+LEAN_EXPORT lean_object* l_Lean_HashSetImp_expand___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheckImp_alreadyVisited___spec__4(lean_object* x_1, lean_object* x_2) {
+_start:
+{
+lean_object* x_3; lean_object* x_4; lean_object* x_5; lean_object* x_6; lean_object* x_7; lean_object* x_8; lean_object* x_9; lean_object* x_10; 
+x_3 = lean_array_get_size(x_2);
+x_4 = lean_unsigned_to_nat(2u);
+x_5 = lean_nat_mul(x_3, x_4);
+lean_dec(x_3);
+x_6 = lean_box(0);
+x_7 = lean_mk_array(x_5, x_6);
+x_8 = lean_unsigned_to_nat(0u);
+x_9 = l_Lean_HashSetImp_moveEntries___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheckImp_alreadyVisited___spec__5(x_8, x_2, x_7);
+x_10 = lean_alloc_ctor(0, 2, 0);
+lean_ctor_set(x_10, 0, x_1);
+lean_ctor_set(x_10, 1, x_9);
+return x_10;
+}
+}
+LEAN_EXPORT lean_object* l_List_replace___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheckImp_alreadyVisited___spec__8(lean_object* x_1, lean_object* x_2, lean_object* x_3) {
+_start:
+{
+if (lean_obj_tag(x_1) == 0)
+{
+lean_object* x_4; 
+lean_dec(x_3);
+x_4 = lean_box(0);
+return x_4;
+}
+else
+{
+uint8_t x_5; 
+x_5 = !lean_is_exclusive(x_1);
+if (x_5 == 0)
+{
+lean_object* x_6; lean_object* x_7; size_t x_8; size_t x_9; uint8_t x_10; 
+x_6 = lean_ctor_get(x_1, 0);
+x_7 = lean_ctor_get(x_1, 1);
+x_8 = lean_ptr_addr(x_2);
+x_9 = lean_ptr_addr(x_6);
+x_10 = lean_usize_dec_eq(x_8, x_9);
+if (x_10 == 0)
+{
+lean_object* x_11; 
+x_11 = l_List_replace___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheckImp_alreadyVisited___spec__8(x_7, x_2, x_3);
+lean_ctor_set(x_1, 1, x_11);
+return x_1;
+}
+else
+{
+lean_dec(x_6);
+lean_ctor_set(x_1, 0, x_3);
+return x_1;
+}
+}
+else
+{
+lean_object* x_12; lean_object* x_13; size_t x_14; size_t x_15; uint8_t x_16; 
+x_12 = lean_ctor_get(x_1, 0);
+x_13 = lean_ctor_get(x_1, 1);
+lean_inc(x_13);
+lean_inc(x_12);
+lean_dec(x_1);
+x_14 = lean_ptr_addr(x_2);
+x_15 = lean_ptr_addr(x_12);
+x_16 = lean_usize_dec_eq(x_14, x_15);
+if (x_16 == 0)
+{
+lean_object* x_17; lean_object* x_18; 
+x_17 = l_List_replace___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheckImp_alreadyVisited___spec__8(x_13, x_2, x_3);
+x_18 = lean_alloc_ctor(1, 2, 0);
+lean_ctor_set(x_18, 0, x_12);
+lean_ctor_set(x_18, 1, x_17);
+return x_18;
+}
+else
+{
+lean_object* x_19; 
+lean_dec(x_12);
+x_19 = lean_alloc_ctor(1, 2, 0);
+lean_ctor_set(x_19, 0, x_3);
+lean_ctor_set(x_19, 1, x_13);
+return x_19;
+}
+}
+}
+}
+}
+LEAN_EXPORT lean_object* l_Lean_HashSetImp_insert___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheckImp_alreadyVisited___spec__3(lean_object* x_1, lean_object* x_2) {
+_start:
+{
+uint8_t x_3; 
+x_3 = !lean_is_exclusive(x_1);
+if (x_3 == 0)
+{
+lean_object* x_4; lean_object* x_5; lean_object* x_6; size_t x_7; uint64_t x_8; uint64_t x_9; uint64_t x_10; size_t x_11; lean_object* x_12; uint8_t x_13; 
+x_4 = lean_ctor_get(x_1, 0);
+x_5 = lean_ctor_get(x_1, 1);
+x_6 = lean_array_get_size(x_5);
+x_7 = lean_ptr_addr(x_2);
+x_8 = lean_usize_to_uint64(x_7);
+x_9 = 11;
+x_10 = lean_uint64_mix_hash(x_8, x_9);
+lean_inc(x_6);
+x_11 = lean_hashset_mk_idx(x_6, x_10);
+x_12 = lean_array_uget(x_5, x_11);
+x_13 = l_List_elem___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheckImp_alreadyVisited___spec__2(x_2, x_12);
+if (x_13 == 0)
+{
+lean_object* x_14; lean_object* x_15; lean_object* x_16; lean_object* x_17; uint8_t x_18; 
+x_14 = lean_unsigned_to_nat(1u);
+x_15 = lean_nat_add(x_4, x_14);
+lean_dec(x_4);
+x_16 = lean_alloc_ctor(1, 2, 0);
+lean_ctor_set(x_16, 0, x_2);
+lean_ctor_set(x_16, 1, x_12);
+x_17 = lean_array_uset(x_5, x_11, x_16);
+x_18 = lean_nat_dec_le(x_15, x_6);
+lean_dec(x_6);
+if (x_18 == 0)
+{
+lean_object* x_19; 
+lean_free_object(x_1);
+x_19 = l_Lean_HashSetImp_expand___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheckImp_alreadyVisited___spec__4(x_15, x_17);
+return x_19;
+}
+else
+{
+lean_ctor_set(x_1, 1, x_17);
+lean_ctor_set(x_1, 0, x_15);
+return x_1;
+}
+}
+else
+{
+lean_object* x_20; lean_object* x_21; lean_object* x_22; lean_object* x_23; 
+lean_dec(x_6);
+x_20 = lean_box(0);
+x_21 = lean_array_uset(x_5, x_11, x_20);
+lean_inc(x_2);
+x_22 = l_List_replace___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheckImp_alreadyVisited___spec__8(x_12, x_2, x_2);
+lean_dec(x_2);
+x_23 = lean_array_uset(x_21, x_11, x_22);
+lean_ctor_set(x_1, 1, x_23);
+return x_1;
+}
+}
+else
+{
+lean_object* x_24; lean_object* x_25; lean_object* x_26; size_t x_27; uint64_t x_28; uint64_t x_29; uint64_t x_30; size_t x_31; lean_object* x_32; uint8_t x_33; 
+x_24 = lean_ctor_get(x_1, 0);
+x_25 = lean_ctor_get(x_1, 1);
+lean_inc(x_25);
+lean_inc(x_24);
+lean_dec(x_1);
+x_26 = lean_array_get_size(x_25);
+x_27 = lean_ptr_addr(x_2);
+x_28 = lean_usize_to_uint64(x_27);
+x_29 = 11;
+x_30 = lean_uint64_mix_hash(x_28, x_29);
+lean_inc(x_26);
+x_31 = lean_hashset_mk_idx(x_26, x_30);
+x_32 = lean_array_uget(x_25, x_31);
+x_33 = l_List_elem___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheckImp_alreadyVisited___spec__2(x_2, x_32);
+if (x_33 == 0)
+{
+lean_object* x_34; lean_object* x_35; lean_object* x_36; lean_object* x_37; uint8_t x_38; 
+x_34 = lean_unsigned_to_nat(1u);
+x_35 = lean_nat_add(x_24, x_34);
+lean_dec(x_24);
+x_36 = lean_alloc_ctor(1, 2, 0);
+lean_ctor_set(x_36, 0, x_2);
+lean_ctor_set(x_36, 1, x_32);
+x_37 = lean_array_uset(x_25, x_31, x_36);
+x_38 = lean_nat_dec_le(x_35, x_26);
+lean_dec(x_26);
+if (x_38 == 0)
+{
+lean_object* x_39; 
+x_39 = l_Lean_HashSetImp_expand___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheckImp_alreadyVisited___spec__4(x_35, x_37);
+return x_39;
+}
+else
+{
+lean_object* x_40; 
+x_40 = lean_alloc_ctor(0, 2, 0);
+lean_ctor_set(x_40, 0, x_35);
+lean_ctor_set(x_40, 1, x_37);
+return x_40;
+}
+}
+else
+{
+lean_object* x_41; lean_object* x_42; lean_object* x_43; lean_object* x_44; lean_object* x_45; 
+lean_dec(x_26);
+x_41 = lean_box(0);
+x_42 = lean_array_uset(x_25, x_31, x_41);
+lean_inc(x_2);
+x_43 = l_List_replace___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheckImp_alreadyVisited___spec__8(x_32, x_2, x_2);
+lean_dec(x_2);
+x_44 = lean_array_uset(x_42, x_31, x_43);
+x_45 = lean_alloc_ctor(0, 2, 0);
+lean_ctor_set(x_45, 0, x_24);
+lean_ctor_set(x_45, 1, x_44);
+return x_45;
+}
+}
+}
+}
 LEAN_EXPORT lean_object* l___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheckImp_alreadyVisited(lean_object* x_1, lean_object* x_2) {
 _start:
 {
 uint8_t x_3; 
-x_3 = l_Lean_HashSetImp_contains___at_Lean_Expr_FindImpl_checkVisited___spec__8(x_2, x_1);
+x_3 = l_Lean_HashSetImp_contains___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheckImp_alreadyVisited___spec__1(x_2, x_1);
 if (x_3 == 0)
 {
 lean_object* x_4; uint8_t x_5; lean_object* x_6; lean_object* x_7; 
-x_4 = l_Lean_HashSetImp_insert___at_Lean_Expr_FindImpl_checkVisited___spec__1(x_2, x_1);
+x_4 = l_Lean_HashSetImp_insert___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheckImp_alreadyVisited___spec__3(x_2, x_1);
 x_5 = 0;
 x_6 = lean_box(x_5);
 x_7 = lean_alloc_ctor(0, 2, 0);
@@ -43557,6 +43966,37 @@ return x_10;
 }
 }
 }
+LEAN_EXPORT lean_object* l_List_elem___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheckImp_alreadyVisited___spec__2___boxed(lean_object* x_1, lean_object* x_2) {
+_start:
+{
+uint8_t x_3; lean_object* x_4; 
+x_3 = l_List_elem___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheckImp_alreadyVisited___spec__2(x_1, x_2);
+lean_dec(x_2);
+lean_dec(x_1);
+x_4 = lean_box(x_3);
+return x_4;
+}
+}
+LEAN_EXPORT lean_object* l_Lean_HashSetImp_contains___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheckImp_alreadyVisited___spec__1___boxed(lean_object* x_1, lean_object* x_2) {
+_start:
+{
+uint8_t x_3; lean_object* x_4; 
+x_3 = l_Lean_HashSetImp_contains___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheckImp_alreadyVisited___spec__1(x_1, x_2);
+lean_dec(x_2);
+lean_dec(x_1);
+x_4 = lean_box(x_3);
+return x_4;
+}
+}
+LEAN_EXPORT lean_object* l_List_replace___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheckImp_alreadyVisited___spec__8___boxed(lean_object* x_1, lean_object* x_2, lean_object* x_3) {
+_start:
+{
+lean_object* x_4; 
+x_4 = l_List_replace___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheckImp_alreadyVisited___spec__8(x_1, x_2, x_3);
+lean_dec(x_2);
+return x_4;
+}
+}
 LEAN_EXPORT lean_object* l_Lean_getExprMVarAssignment_x3f___at___private_Lean_Meta_ExprDefEq_0__Lean_Meta_typeOccursCheckImp_occursCheck___spec__4(lean_object* x_1, lean_object* x_2, lean_object* x_3) {
 _start:
 {
diff --git a/stage0/stdlib/Lean/Meta/FunInfo.c b/stage0/stdlib/Lean/Meta/FunInfo.c
index 9ff4b983a6..ce04d6a4a8 100644
--- a/stage0/stdlib/Lean/Meta/FunInfo.c
+++ b/stage0/stdlib/Lean/Meta/FunInfo.c
@@ -92,7 +92,6 @@ LEAN_EXPORT lean_object* l_Lean_Meta_FunInfo_getArity___boxed(lean_object*);
 lean_object* l_instMonadControlTOfPure___rarg(lean_object*);
 static lean_object* l_Std_Range_forIn_loop___at___private_Lean_Meta_FunInfo_0__Lean_Meta_getFunInfoAux___spec__3___lambda__1___closed__2;
 LEAN_EXPORT lean_object* l___private_Lean_Meta_FunInfo_0__Lean_Meta_collectDeps___boxed(lean_object*, lean_object*);
-lean_object* l_Lean_Expr_FindImpl_findUnsafe_x3f(lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l___private_Lean_Meta_FunInfo_0__Lean_Meta_whenHasVar___rarg___boxed(lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Std_Range_forIn_loop___at___private_Lean_Meta_FunInfo_0__Lean_Meta_getFunInfoAux___spec__3___at___private_Lean_Meta_FunInfo_0__Lean_Meta_getFunInfoAux___spec__4(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Array_anyMUnsafe_any___at___private_Lean_Meta_FunInfo_0__Lean_Meta_collectDeps_visit___spec__3___boxed(lean_object*, lean_object*, lean_object*, lean_object*);
@@ -135,6 +134,7 @@ lean_object* l___private_Lean_Expr_0__Lean_Expr_getAppArgsAux(lean_object*, lean
 lean_object* lean_array_get_size(lean_object*);
 LEAN_EXPORT lean_object* l_Std_Range_forIn_loop___at___private_Lean_Meta_FunInfo_0__Lean_Meta_getFunInfoAux___spec__3___at___private_Lean_Meta_FunInfo_0__Lean_Meta_getFunInfoAux___spec__4___boxed(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 lean_object* lean_infer_type(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
+lean_object* lean_find_expr(lean_object*, lean_object*);
 uint8_t lean_nat_dec_le(lean_object*, lean_object*);
 LEAN_EXPORT uint8_t l_Array_contains___at___private_Lean_Meta_FunInfo_0__Lean_Meta_collectDeps_visit___spec__2(lean_object*, lean_object*);
 lean_object* lean_nat_add(lean_object*, lean_object*);
@@ -2814,8 +2814,8 @@ lean_object* x_161; lean_object* x_162;
 lean_inc(x_26);
 x_161 = lean_alloc_closure((void*)(l_Std_Range_forIn_loop___at___private_Lean_Meta_FunInfo_0__Lean_Meta_getFunInfoAux___spec__3___lambda__2___boxed), 2, 1);
 lean_closure_set(x_161, 0, x_26);
-lean_inc(x_33);
-x_162 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_161, x_33);
+x_162 = lean_find_expr(x_161, x_33);
+lean_dec(x_161);
 if (lean_obj_tag(x_162) == 0)
 {
 if (lean_obj_tag(x_152) == 0)
@@ -3729,8 +3729,8 @@ lean_object* x_160; lean_object* x_161;
 lean_inc(x_25);
 x_160 = lean_alloc_closure((void*)(l_Std_Range_forIn_loop___at___private_Lean_Meta_FunInfo_0__Lean_Meta_getFunInfoAux___spec__3___lambda__2___boxed), 2, 1);
 lean_closure_set(x_160, 0, x_25);
-lean_inc(x_32);
-x_161 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_160, x_32);
+x_161 = lean_find_expr(x_160, x_32);
+lean_dec(x_160);
 if (lean_obj_tag(x_161) == 0)
 {
 if (lean_obj_tag(x_151) == 0)
diff --git a/stage0/stdlib/Lean/Meta/Injective.c b/stage0/stdlib/Lean/Meta/Injective.c
index 35a1955627..343c967832 100644
--- a/stage0/stdlib/Lean/Meta/Injective.c
+++ b/stage0/stdlib/Lean/Meta/Injective.c
@@ -195,7 +195,6 @@ static lean_object* l___private_Lean_Util_Trace_0__Lean_getResetTraces___at_Lean
 static double l_Lean_withTraceNode___at_Lean_Meta_mkInjectiveTheorems___spec__5___lambda__2___closed__1;
 lean_object* l_Lean_Core_transform___at_Lean_Core_betaReduce___spec__1(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 lean_object* l_Lean_Meta_withLCtx___at___private_Lean_Meta_Basic_0__Lean_Meta_mkLeveErrorMessageCore___spec__2___rarg(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
-lean_object* l_Lean_Expr_FindImpl_findUnsafe_x3f(lean_object*, lean_object*);
 static lean_object* l_Lean_getConstInfo___at_Lean_Meta_mkInjectiveTheorems___spec__2___closed__1;
 LEAN_EXPORT lean_object* l_Lean_withTraceNode___at_Lean_Meta_mkInjectiveTheorems___spec__5___lambda__2(lean_object*, uint8_t, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, uint8_t, double, double, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l___private_Lean_Meta_Injective_0__Lean_Meta_mkInjectiveEqTheoremValue(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
@@ -261,6 +260,7 @@ static lean_object* l_Lean_isTracingEnabledFor___at_Lean_Meta_mkInjectiveTheorem
 LEAN_EXPORT lean_object* l_Lean_getConstInfo___at_Lean_Meta_mkInjectiveTheorems___spec__2___boxed(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 lean_object* lean_infer_type(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 static lean_object* l_List_forIn_loop___at_Lean_Meta_mkInjectiveTheorems___spec__10___closed__1;
+lean_object* lean_find_expr(lean_object*, lean_object*);
 static lean_object* l_Lean_Meta_initFn____x40_Lean_Meta_Injective___hyg_2306____closed__1;
 uint8_t lean_usize_dec_lt(size_t, size_t);
 lean_object* l_Lean_Meta_intro1Core(lean_object*, uint8_t, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
@@ -546,6 +546,7 @@ lean_object* x_9; uint8_t x_10;
 x_9 = l_Lean_LocalDecl_type(x_7);
 lean_dec(x_7);
 x_10 = l_Lean_Expr_occurs(x_2, x_9);
+lean_dec(x_9);
 return x_10;
 }
 else
@@ -585,7 +586,8 @@ lean_object* x_4; lean_object* x_5;
 x_4 = lean_alloc_closure((void*)(l_Lean_Meta_occursOrInType_go___boxed), 3, 2);
 lean_closure_set(x_4, 0, x_1);
 lean_closure_set(x_4, 1, x_2);
-x_5 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_4, x_3);
+x_5 = lean_find_expr(x_4, x_3);
+lean_dec(x_4);
 if (lean_obj_tag(x_5) == 0)
 {
 uint8_t x_6; 
@@ -606,6 +608,7 @@ _start:
 {
 uint8_t x_4; lean_object* x_5; 
 x_4 = l_Lean_Meta_occursOrInType(x_1, x_2, x_3);
+lean_dec(x_3);
 x_5 = lean_box(x_4);
 return x_5;
 }
@@ -743,7 +746,6 @@ lean_dec(x_19);
 x_24 = lean_array_fget(x_3, x_6);
 x_25 = lean_ctor_get(x_10, 1);
 lean_inc(x_25);
-lean_inc(x_4);
 lean_inc(x_24);
 x_26 = l_Lean_Meta_occursOrInType(x_25, x_24, x_4);
 if (x_26 == 0)
diff --git a/stage0/stdlib/Lean/Meta/Match/Match.c b/stage0/stdlib/Lean/Meta/Match/Match.c
index c891e15305..e135ec491c 100644
--- a/stage0/stdlib/Lean/Meta/Match/Match.c
+++ b/stage0/stdlib/Lean/Meta/Match/Match.c
@@ -38551,12 +38551,10 @@ if (x_66 == 0)
 lean_object* x_67; lean_object* x_68; uint8_t x_69; 
 x_67 = lean_ctor_get(x_61, 0);
 x_68 = lean_ctor_get(x_61, 1);
-lean_inc(x_67);
 x_69 = l_Lean_Expr_hasSorry(x_67);
 if (x_69 == 0)
 {
 uint8_t x_70; 
-lean_inc(x_59);
 x_70 = l_Lean_Expr_hasSorry(x_59);
 if (x_70 == 0)
 {
@@ -38667,12 +38665,10 @@ x_90 = lean_ctor_get(x_61, 1);
 lean_inc(x_90);
 lean_inc(x_89);
 lean_dec(x_61);
-lean_inc(x_89);
 x_91 = l_Lean_Expr_hasSorry(x_89);
 if (x_91 == 0)
 {
 uint8_t x_92; 
-lean_inc(x_59);
 x_92 = l_Lean_Expr_hasSorry(x_59);
 if (x_92 == 0)
 {
@@ -38816,12 +38812,10 @@ if (lean_is_exclusive(x_115)) {
  lean_dec_ref(x_115);
  x_122 = lean_box(0);
 }
-lean_inc(x_120);
 x_123 = l_Lean_Expr_hasSorry(x_120);
 if (x_123 == 0)
 {
 uint8_t x_124; 
-lean_inc(x_113);
 x_124 = l_Lean_Expr_hasSorry(x_113);
 if (x_124 == 0)
 {
@@ -39961,12 +39955,10 @@ if (x_63 == 0)
 lean_object* x_64; lean_object* x_65; uint8_t x_66; 
 x_64 = lean_ctor_get(x_58, 0);
 x_65 = lean_ctor_get(x_58, 1);
-lean_inc(x_64);
 x_66 = l_Lean_Expr_hasSorry(x_64);
 if (x_66 == 0)
 {
 uint8_t x_67; 
-lean_inc(x_56);
 x_67 = l_Lean_Expr_hasSorry(x_56);
 if (x_67 == 0)
 {
@@ -40079,12 +40071,10 @@ x_87 = lean_ctor_get(x_58, 1);
 lean_inc(x_87);
 lean_inc(x_86);
 lean_dec(x_58);
-lean_inc(x_86);
 x_88 = l_Lean_Expr_hasSorry(x_86);
 if (x_88 == 0)
 {
 uint8_t x_89; 
-lean_inc(x_56);
 x_89 = l_Lean_Expr_hasSorry(x_56);
 if (x_89 == 0)
 {
@@ -40230,12 +40220,10 @@ if (lean_is_exclusive(x_112)) {
  lean_dec_ref(x_112);
  x_119 = lean_box(0);
 }
-lean_inc(x_117);
 x_120 = l_Lean_Expr_hasSorry(x_117);
 if (x_120 == 0)
 {
 uint8_t x_121; 
-lean_inc(x_110);
 x_121 = l_Lean_Expr_hasSorry(x_110);
 if (x_121 == 0)
 {
diff --git a/stage0/stdlib/Lean/Meta/Match/MatchEqs.c b/stage0/stdlib/Lean/Meta/Match/MatchEqs.c
index dc6ff4fbb6..dc36470618 100644
--- a/stage0/stdlib/Lean/Meta/Match/MatchEqs.c
+++ b/stage0/stdlib/Lean/Meta/Match/MatchEqs.c
@@ -574,7 +574,6 @@ lean_object* l_Subarray_get___rarg(lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_addTrace___at___private_Lean_Meta_Match_MatchEqs_0__Lean_Meta_Match_mkSplitterProof_convertCastEqRec_go___spec__5(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 lean_object* l_Lean_Meta_withLCtx___at___private_Lean_Meta_Basic_0__Lean_Meta_mkLeveErrorMessageCore___spec__2___rarg(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l___private_Lean_Meta_Match_MatchEqs_0__Lean_Meta_Match_substSomeVar___lambda__2(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
-lean_object* l_Lean_Expr_FindImpl_findUnsafe_x3f(lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l___private_Lean_Meta_Match_MatchEqs_0__Lean_Meta_Match_mkSplitterProof_convertCastEqRec(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 static lean_object* l_Lean_Meta_casesOnStuckLHS___closed__1;
 LEAN_EXPORT lean_object* l___private_Lean_Meta_Match_MatchEqs_0__Lean_Meta_Match_injectionAnyCandidate_x3f___lambda__1___boxed(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
@@ -797,6 +796,7 @@ LEAN_EXPORT lean_object* l_Lean_PersistentArray_forIn___at___private_Lean_Meta_M
 static lean_object* l_Lean_Meta_Match_forallAltTelescope_go___rarg___closed__4;
 static lean_object* l_Lean_Expr_withAppAux___at___private_Lean_Meta_Match_MatchEqs_0__Lean_Meta_Match_mkSplitterProof_convertCastEqRec___spec__8___lambda__11___closed__3;
 lean_object* lean_infer_type(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
+lean_object* lean_find_expr(lean_object*, lean_object*);
 uint8_t lean_nat_dec_le(lean_object*, lean_object*);
 static lean_object* l___private_Lean_Meta_Match_MatchEqs_0__Lean_Meta_Match_injectionAnyCandidate_x3f___closed__1;
 LEAN_EXPORT lean_object* l___private_Lean_Meta_Match_MatchEqs_0__Lean_Meta_Match_mkSplitterProof_mkMap(lean_object*, lean_object*, lean_object*, lean_object*);
@@ -5960,7 +5960,8 @@ _start:
 lean_object* x_3; lean_object* x_4; 
 x_3 = lean_alloc_closure((void*)(l_Lean_Meta_Match_forallAltTelescope_isNamedPatternProof___lambda__1___boxed), 2, 1);
 lean_closure_set(x_3, 0, x_2);
-x_4 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_3, x_1);
+x_4 = lean_find_expr(x_3, x_1);
+lean_dec(x_3);
 if (lean_obj_tag(x_4) == 0)
 {
 uint8_t x_5; 
@@ -5992,6 +5993,7 @@ _start:
 {
 uint8_t x_3; lean_object* x_4; 
 x_3 = l_Lean_Meta_Match_forallAltTelescope_isNamedPatternProof(x_1, x_2);
+lean_dec(x_1);
 x_4 = lean_box(x_3);
 return x_4;
 }
@@ -6788,7 +6790,6 @@ else
 {
 uint8_t x_38; 
 lean_inc(x_12);
-lean_inc(x_18);
 x_38 = l_Lean_Meta_Match_forallAltTelescope_isNamedPatternProof(x_18, x_12);
 if (x_38 == 0)
 {
diff --git a/stage0/stdlib/Lean/Meta/RecursorInfo.c b/stage0/stdlib/Lean/Meta/RecursorInfo.c
index ea2072e3cb..6194815d5e 100644
--- a/stage0/stdlib/Lean/Meta/RecursorInfo.c
+++ b/stage0/stdlib/Lean/Meta/RecursorInfo.c
@@ -222,7 +222,6 @@ static lean_object* l_Lean_Expr_withAppAux___at___private_Lean_Meta_RecursorInfo
 LEAN_EXPORT lean_object* l___private_Lean_Meta_RecursorInfo_0__Lean_Meta_checkMotiveResultType___boxed(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 static lean_object* l_Lean_Meta_initFn____x40_Lean_Meta_RecursorInfo___hyg_2934____lambda__2___closed__10;
 static lean_object* l_List_toString___at_Lean_Meta_RecursorInfo_instToString___spec__7___closed__1;
-lean_object* l_Lean_Expr_FindImpl_findUnsafe_x3f(lean_object*, lean_object*);
 static lean_object* l___private_Lean_Meta_RecursorInfo_0__Lean_Meta_getParamsPos___closed__1;
 LEAN_EXPORT lean_object* l___private_Lean_Meta_RecursorInfo_0__Lean_Meta_getParamsPos___boxed(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_Expr_withAppAux___at___private_Lean_Meta_RecursorInfo_0__Lean_Meta_mkRecursorInfoAux___spec__2___boxed(lean_object**);
@@ -307,6 +306,7 @@ static lean_object* l_Lean_Meta_initFn____x40_Lean_Meta_RecursorInfo___hyg_2934_
 lean_object* lean_infer_type(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 static lean_object* l___private_Lean_Meta_RecursorInfo_0__Lean_Meta_checkMotive___closed__4;
 uint8_t lean_level_eq(lean_object*, lean_object*);
+lean_object* lean_find_expr(lean_object*, lean_object*);
 uint8_t lean_nat_dec_le(lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l___private_Lean_Meta_RecursorInfo_0__Lean_Meta_checkMotive(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 uint8_t lean_usize_dec_lt(size_t, size_t);
@@ -5168,7 +5168,9 @@ x_15 = lean_ctor_get(x_12, 1);
 lean_inc(x_1);
 x_16 = lean_alloc_closure((void*)(l_Array_getIdx_x3f___at___private_Lean_Meta_RecursorInfo_0__Lean_Meta_getMajorPosDepElim___spec__1___lambda__1___boxed), 2, 1);
 lean_closure_set(x_16, 0, x_1);
-x_17 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_16, x_14);
+x_17 = lean_find_expr(x_16, x_14);
+lean_dec(x_14);
+lean_dec(x_16);
 if (lean_obj_tag(x_17) == 0)
 {
 size_t x_18; size_t x_19; 
@@ -5205,7 +5207,9 @@ lean_dec(x_12);
 lean_inc(x_1);
 x_25 = lean_alloc_closure((void*)(l_Array_getIdx_x3f___at___private_Lean_Meta_RecursorInfo_0__Lean_Meta_getMajorPosDepElim___spec__1___lambda__1___boxed), 2, 1);
 lean_closure_set(x_25, 0, x_1);
-x_26 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_25, x_23);
+x_26 = lean_find_expr(x_25, x_23);
+lean_dec(x_23);
+lean_dec(x_25);
 if (lean_obj_tag(x_26) == 0)
 {
 size_t x_27; size_t x_28; 
diff --git a/stage0/stdlib/Lean/Meta/Tactic/Acyclic.c b/stage0/stdlib/Lean/Meta/Tactic/Acyclic.c
index 4730eaa884..518825fa74 100644
--- a/stage0/stdlib/Lean/Meta/Tactic/Acyclic.c
+++ b/stage0/stdlib/Lean/Meta/Tactic/Acyclic.c
@@ -144,7 +144,6 @@ return x_11;
 else
 {
 uint8_t x_12; 
-lean_inc(x_2);
 x_12 = l_Lean_Expr_occurs(x_1, x_2);
 if (x_12 == 0)
 {
diff --git a/stage0/stdlib/Lean/Meta/Tactic/Contradiction.c b/stage0/stdlib/Lean/Meta/Tactic/Contradiction.c
index 52a52b34f7..67f777a814 100644
--- a/stage0/stdlib/Lean/Meta/Tactic/Contradiction.c
+++ b/stage0/stdlib/Lean/Meta/Tactic/Contradiction.c
@@ -195,7 +195,6 @@ static lean_object* l_Lean_Meta_initFn____x40_Lean_Meta_Tactic_Contradiction___h
 static lean_object* l_Lean_Meta_ElimEmptyInductive_elim___lambda__3___closed__4;
 LEAN_EXPORT lean_object* l_Lean_PersistentArray_forInAux___at_Lean_MVarId_contradictionCore___spec__2___lambda__1(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 static lean_object* l_Lean_Meta_initFn____x40_Lean_Meta_Tactic_Contradiction___hyg_4434____closed__11;
-lean_object* l_Lean_Expr_FindImpl_findUnsafe_x3f(lean_object*, lean_object*);
 static lean_object* l_Lean_Meta_initFn____x40_Lean_Meta_Tactic_Contradiction___hyg_4434____closed__8;
 static lean_object* l_Lean_Meta_ElimEmptyInductive_elim___lambda__7___closed__1;
 static lean_object* l_Lean_MVarId_contradictionCore___closed__4;
@@ -263,6 +262,7 @@ lean_object* lean_array_get_size(lean_object*);
 lean_object* l_Lean_LocalDecl_toExpr(lean_object*);
 LEAN_EXPORT lean_object* l_Array_forInUnsafe_loop___at_Lean_MVarId_contradictionCore___spec__4___lambda__1(lean_object*, lean_object*, uint8_t, uint8_t, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 lean_object* lean_infer_type(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
+lean_object* lean_find_expr(lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l___private_Lean_Meta_Tactic_Contradiction_0__Lean_Meta_processGenDiseq___lambda__1(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 uint8_t lean_usize_dec_lt(size_t, size_t);
 LEAN_EXPORT uint8_t l_Lean_Meta_Contradiction_Config_useDecide___default;
@@ -400,7 +400,8 @@ lean_object* x_9; lean_object* x_10; lean_object* x_11; lean_object* x_12;
 x_9 = lean_ctor_get(x_7, 0);
 x_10 = lean_ctor_get(x_7, 1);
 x_11 = l___private_Lean_Meta_Tactic_Contradiction_0__Lean_Meta_nestedFalseElim___closed__1;
-x_12 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_11, x_9);
+x_12 = lean_find_expr(x_11, x_9);
+lean_dec(x_9);
 if (lean_obj_tag(x_12) == 0)
 {
 uint8_t x_13; lean_object* x_14; 
@@ -543,7 +544,8 @@ lean_inc(x_41);
 lean_inc(x_40);
 lean_dec(x_7);
 x_42 = l___private_Lean_Meta_Tactic_Contradiction_0__Lean_Meta_nestedFalseElim___closed__1;
-x_43 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_42, x_40);
+x_43 = lean_find_expr(x_42, x_40);
+lean_dec(x_40);
 if (lean_obj_tag(x_43) == 0)
 {
 uint8_t x_44; lean_object* x_45; lean_object* x_46; 
diff --git a/stage0/stdlib/Lean/Meta/Tactic/Simp/SimpCongrTheorems.c b/stage0/stdlib/Lean/Meta/Tactic/Simp/SimpCongrTheorems.c
index 12514affc7..de4378eb35 100644
--- a/stage0/stdlib/Lean/Meta/Tactic/Simp/SimpCongrTheorems.c
+++ b/stage0/stdlib/Lean/Meta/Tactic/Simp/SimpCongrTheorems.c
@@ -258,7 +258,6 @@ LEAN_EXPORT lean_object* l_Lean_HashMapImp_find_x3f___at_Lean_Meta_SimpCongrTheo
 static lean_object* l_Array_forInUnsafe_loop___at_Lean_Meta_mkSimpCongrTheorem___spec__6___closed__4;
 LEAN_EXPORT lean_object* l_Array_forInUnsafe_loop___at_Lean_Meta_mkSimpCongrTheorem___spec__5___lambda__1(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 static lean_object* l_Lean_Meta_initFn____x40_Lean_Meta_Tactic_Simp_SimpCongrTheorems___hyg_1872____lambda__1___closed__5;
-lean_object* l_Lean_Expr_FindImpl_findUnsafe_x3f(lean_object*, lean_object*);
 LEAN_EXPORT uint8_t l_Lean_AssocList_contains___at_Lean_Meta_addSimpCongrTheoremEntry___spec__7(lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_Meta_initFn____x40_Lean_Meta_Tactic_Simp_SimpCongrTheorems___hyg_1872____lambda__2___boxed(lean_object*, lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_HashMapImp_moveEntries___at_Lean_Meta_addSimpCongrTheoremEntry___spec__9(lean_object*, lean_object*, lean_object*);
@@ -346,6 +345,7 @@ lean_object* l_List_map___at_Lean_mkConstWithLevelParams___spec__1(lean_object*)
 lean_object* lean_array_get_size(lean_object*);
 lean_object* lean_infer_type(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Array_forInUnsafe_loop___at_Lean_Meta_mkSimpCongrTheorem___spec__7___lambda__5___boxed(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
+lean_object* lean_find_expr(lean_object*, lean_object*);
 static lean_object* l_Array_forInUnsafe_loop___at_Lean_Meta_mkSimpCongrTheorem___spec__7___lambda__5___closed__6;
 uint8_t lean_nat_dec_le(lean_object*, lean_object*);
 static lean_object* l___private_Lean_Meta_Tactic_Simp_SimpCongrTheorems_0__Lean_Meta_reprSimpCongrTheorem____x40_Lean_Meta_Tactic_Simp_SimpCongrTheorems___hyg_53____closed__26;
@@ -3687,7 +3687,8 @@ _start:
 lean_object* x_3; lean_object* x_4; 
 x_3 = lean_alloc_closure((void*)(l_Lean_Meta_mkSimpCongrTheorem_onlyMVarsAt___lambda__1___boxed), 2, 1);
 lean_closure_set(x_3, 0, x_2);
-x_4 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_3, x_1);
+x_4 = lean_find_expr(x_3, x_1);
+lean_dec(x_3);
 if (lean_obj_tag(x_4) == 0)
 {
 uint8_t x_5; 
@@ -3719,6 +3720,7 @@ _start:
 {
 uint8_t x_3; lean_object* x_4; 
 x_3 = l_Lean_Meta_mkSimpCongrTheorem_onlyMVarsAt(x_1, x_2);
+lean_dec(x_1);
 x_4 = lean_box(x_3);
 return x_4;
 }
@@ -4042,7 +4044,6 @@ lean_inc(x_17);
 lean_dec(x_15);
 x_18 = l_Array_forInUnsafe_loop___at_Lean_Meta_mkSimpCongrTheorem___spec__5___closed__1;
 lean_inc(x_1);
-lean_inc(x_16);
 x_19 = l_Lean_Meta_mkSimpCongrTheorem_onlyMVarsAt(x_16, x_1);
 if (x_19 == 0)
 {
@@ -4797,7 +4798,6 @@ x_19 = lean_ctor_get(x_18, 1);
 lean_inc(x_19);
 lean_dec(x_18);
 lean_inc(x_1);
-lean_inc(x_13);
 x_20 = l_Lean_Meta_mkSimpCongrTheorem_onlyMVarsAt(x_13, x_1);
 if (x_20 == 0)
 {
@@ -4921,7 +4921,6 @@ x_50 = lean_ctor_get(x_49, 1);
 lean_inc(x_50);
 lean_dec(x_49);
 lean_inc(x_1);
-lean_inc(x_44);
 x_51 = l_Lean_Meta_mkSimpCongrTheorem_onlyMVarsAt(x_44, x_1);
 if (x_51 == 0)
 {
diff --git a/stage0/stdlib/Lean/Meta/Tactic/Split.c b/stage0/stdlib/Lean/Meta/Tactic/Split.c
index 9060c93318..f379f798be 100644
--- a/stage0/stdlib/Lean/Meta/Tactic/Split.c
+++ b/stage0/stdlib/Lean/Meta/Tactic/Split.c
@@ -333,7 +333,6 @@ LEAN_EXPORT lean_object* l___private_Lean_Meta_Tactic_Split_0__Lean_Meta_Split_s
 static lean_object* l_Lean_Meta_Split_initFn____x40_Lean_Meta_Tactic_Split___hyg_906____closed__1;
 lean_object* l_Lean_Meta_introNCore(lean_object*, lean_object*, lean_object*, uint8_t, uint8_t, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Array_forInUnsafe_loop___at___private_Lean_Meta_Tactic_Split_0__Lean_Meta_Split_substDiscrEqs___spec__1___boxed(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
-lean_object* l_Lean_Expr_FindImpl_findUnsafe_x3f(lean_object*, lean_object*);
 static lean_object* l_List_foldlM___at_Lean_Meta_Split_applyMatchSplitter___spec__2___closed__2;
 lean_object* l_Lean_instAddErrorMessageContextOfAddMessageContextOfMonad___rarg(lean_object*, lean_object*, lean_object*, lean_object*);
 lean_object* l_Lean_Meta_heqToEq(lean_object*, lean_object*, uint8_t, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
@@ -458,6 +457,7 @@ static lean_object* l___private_Lean_Meta_Tactic_Split_0__Lean_Meta_Split_genera
 static lean_object* l_Lean_Meta_Split_applyMatchSplitter___lambda__3___closed__7;
 static lean_object* l_Lean_Meta_Split_applyMatchSplitter___lambda__4___closed__1;
 lean_object* lean_infer_type(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
+lean_object* lean_find_expr(lean_object*, lean_object*);
 uint8_t lean_nat_dec_le(lean_object*, lean_object*);
 extern lean_object* l_Lean_Meta_instAddMessageContextMetaM;
 LEAN_EXPORT lean_object* l_Lean_Meta_splitTarget_x3f_go(lean_object*, uint8_t, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
@@ -13654,12 +13654,11 @@ x_6 = lean_alloc_closure((void*)(l_Lean_Meta_Split_findSplit_x3f_isCandidate___b
 lean_closure_set(x_6, 0, x_1);
 lean_closure_set(x_6, 1, x_5);
 lean_closure_set(x_6, 2, x_3);
-lean_inc(x_4);
-x_7 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_6, x_4);
+x_7 = lean_find_expr(x_6, x_4);
+lean_dec(x_6);
 if (lean_obj_tag(x_7) == 0)
 {
 lean_object* x_8; 
-lean_dec(x_4);
 lean_dec(x_3);
 lean_dec(x_1);
 x_8 = lean_box(0);
@@ -13678,7 +13677,6 @@ if (x_11 == 0)
 {
 uint8_t x_12; 
 x_12 = l_Lean_Expr_isDIte(x_4);
-lean_dec(x_4);
 if (x_12 == 0)
 {
 lean_dec(x_3);
@@ -13691,6 +13689,7 @@ lean_object* x_13; lean_object* x_14; lean_object* x_15;
 x_13 = l_Lean_Meta_Split_findSplit_x3f_isCandidate___closed__5;
 x_14 = l_Lean_Expr_getRevArg_x21(x_10, x_13);
 x_15 = l_Lean_Meta_Split_findSplit_x3f_go(x_1, x_2, x_3, x_14);
+lean_dec(x_14);
 if (lean_obj_tag(x_15) == 0)
 {
 return x_7;
@@ -13721,10 +13720,10 @@ return x_18;
 else
 {
 lean_object* x_19; lean_object* x_20; lean_object* x_21; 
-lean_dec(x_4);
 x_19 = l_Lean_Meta_Split_findSplit_x3f_isCandidate___closed__5;
 x_20 = l_Lean_Expr_getRevArg_x21(x_10, x_19);
 x_21 = l_Lean_Meta_Split_findSplit_x3f_go(x_1, x_2, x_3, x_20);
+lean_dec(x_20);
 if (lean_obj_tag(x_21) == 0)
 {
 return x_7;
@@ -13763,7 +13762,6 @@ if (x_26 == 0)
 {
 uint8_t x_27; 
 x_27 = l_Lean_Expr_isDIte(x_4);
-lean_dec(x_4);
 if (x_27 == 0)
 {
 lean_object* x_28; 
@@ -13779,6 +13777,7 @@ lean_object* x_29; lean_object* x_30; lean_object* x_31;
 x_29 = l_Lean_Meta_Split_findSplit_x3f_isCandidate___closed__5;
 x_30 = l_Lean_Expr_getRevArg_x21(x_25, x_29);
 x_31 = l_Lean_Meta_Split_findSplit_x3f_go(x_1, x_2, x_3, x_30);
+lean_dec(x_30);
 if (lean_obj_tag(x_31) == 0)
 {
 lean_object* x_32; 
@@ -13812,10 +13811,10 @@ return x_35;
 else
 {
 lean_object* x_36; lean_object* x_37; lean_object* x_38; 
-lean_dec(x_4);
 x_36 = l_Lean_Meta_Split_findSplit_x3f_isCandidate___closed__5;
 x_37 = l_Lean_Expr_getRevArg_x21(x_25, x_36);
 x_38 = l_Lean_Meta_Split_findSplit_x3f_go(x_1, x_2, x_3, x_37);
+lean_dec(x_37);
 if (lean_obj_tag(x_38) == 0)
 {
 lean_object* x_39; 
@@ -13856,6 +13855,7 @@ uint8_t x_5; lean_object* x_6;
 x_5 = lean_unbox(x_2);
 lean_dec(x_2);
 x_6 = l_Lean_Meta_Split_findSplit_x3f_go(x_1, x_5, x_3, x_4);
+lean_dec(x_4);
 return x_6;
 }
 }
@@ -13874,6 +13874,7 @@ uint8_t x_5; lean_object* x_6;
 x_5 = lean_unbox(x_3);
 lean_dec(x_3);
 x_6 = l_Lean_Meta_Split_findSplit_x3f(x_1, x_2, x_5, x_4);
+lean_dec(x_2);
 return x_6;
 }
 }
@@ -13969,14 +13970,12 @@ x_13 = lean_ctor_get(x_10, 1);
 x_14 = lean_ctor_get(x_12, 0);
 lean_inc(x_14);
 lean_dec(x_12);
-lean_inc(x_3);
 lean_inc(x_4);
 x_15 = l_Lean_Meta_Split_findSplit_x3f_go(x_14, x_2, x_4, x_3);
 if (lean_obj_tag(x_15) == 0)
 {
 lean_object* x_16; lean_object* x_17; uint8_t x_18; 
 lean_dec(x_4);
-lean_dec(x_3);
 x_16 = l_Array_forInUnsafe_loop___at___private_Lean_Meta_Tactic_Split_0__Lean_Meta_Split_generalizeMatchDiscrs_mkNewTarget___spec__4___closed__3;
 x_17 = l_Lean_isTracingEnabledFor___at_Lean_Meta_processPostponed_loop___spec__1(x_16, x_5, x_6, x_7, x_8, x_13);
 x_18 = !lean_is_exclusive(x_17);
@@ -14098,7 +14097,6 @@ lean_dec(x_7);
 lean_dec(x_6);
 lean_dec(x_5);
 lean_dec(x_4);
-lean_dec(x_3);
 lean_dec(x_1);
 x_51 = !lean_is_exclusive(x_50);
 if (x_51 == 0)
@@ -14289,7 +14287,6 @@ lean_dec(x_7);
 lean_dec(x_6);
 lean_dec(x_5);
 lean_dec(x_4);
-lean_dec(x_3);
 lean_dec(x_1);
 return x_50;
 }
@@ -14303,7 +14300,6 @@ lean_dec(x_7);
 lean_dec(x_6);
 lean_dec(x_5);
 lean_dec(x_4);
-lean_dec(x_3);
 lean_dec(x_1);
 return x_50;
 }
@@ -14444,7 +14440,6 @@ lean_dec(x_7);
 lean_dec(x_6);
 lean_dec(x_5);
 lean_dec(x_4);
-lean_dec(x_3);
 lean_dec(x_1);
 x_148 = lean_alloc_ctor(1, 2, 0);
 lean_ctor_set(x_148, 0, x_109);
@@ -14462,7 +14457,6 @@ lean_dec(x_7);
 lean_dec(x_6);
 lean_dec(x_5);
 lean_dec(x_4);
-lean_dec(x_3);
 lean_dec(x_1);
 x_149 = lean_alloc_ctor(1, 2, 0);
 lean_ctor_set(x_149, 0, x_109);
@@ -14479,7 +14473,6 @@ lean_free_object(x_15);
 lean_dec(x_47);
 lean_free_object(x_10);
 lean_dec(x_4);
-lean_dec(x_3);
 x_150 = lean_box(0);
 x_151 = l_Lean_Meta_splitIfTarget_x3f(x_1, x_150, x_5, x_6, x_7, x_8, x_13);
 if (lean_obj_tag(x_151) == 0)
@@ -14750,7 +14743,6 @@ lean_free_object(x_15);
 lean_dec(x_47);
 lean_free_object(x_10);
 lean_dec(x_4);
-lean_dec(x_3);
 x_204 = lean_box(0);
 x_205 = l_Lean_Meta_splitIfTarget_x3f(x_1, x_204, x_5, x_6, x_7, x_8, x_13);
 if (lean_obj_tag(x_205) == 0)
@@ -15045,7 +15037,6 @@ lean_dec(x_7);
 lean_dec(x_6);
 lean_dec(x_5);
 lean_dec(x_4);
-lean_dec(x_3);
 lean_dec(x_1);
 x_262 = lean_ctor_get(x_261, 0);
 lean_inc(x_262);
@@ -15214,7 +15205,6 @@ lean_dec(x_7);
 lean_dec(x_6);
 lean_dec(x_5);
 lean_dec(x_4);
-lean_dec(x_3);
 lean_dec(x_1);
 if (lean_is_scalar(x_269)) {
  x_307 = lean_alloc_ctor(1, 2, 0);
@@ -15236,7 +15226,6 @@ lean_dec(x_7);
 lean_dec(x_6);
 lean_dec(x_5);
 lean_dec(x_4);
-lean_dec(x_3);
 lean_dec(x_1);
 if (lean_is_scalar(x_269)) {
  x_308 = lean_alloc_ctor(1, 2, 0);
@@ -15255,7 +15244,6 @@ lean_object* x_309; lean_object* x_310;
 lean_dec(x_258);
 lean_free_object(x_10);
 lean_dec(x_4);
-lean_dec(x_3);
 x_309 = lean_box(0);
 x_310 = l_Lean_Meta_splitIfTarget_x3f(x_1, x_309, x_5, x_6, x_7, x_8, x_13);
 if (lean_obj_tag(x_310) == 0)
@@ -15397,7 +15385,6 @@ lean_object* x_334; lean_object* x_335;
 lean_dec(x_258);
 lean_free_object(x_10);
 lean_dec(x_4);
-lean_dec(x_3);
 x_334 = lean_box(0);
 x_335 = l_Lean_Meta_splitIfTarget_x3f(x_1, x_334, x_5, x_6, x_7, x_8, x_13);
 if (lean_obj_tag(x_335) == 0)
@@ -15546,14 +15533,12 @@ lean_dec(x_10);
 x_361 = lean_ctor_get(x_359, 0);
 lean_inc(x_361);
 lean_dec(x_359);
-lean_inc(x_3);
 lean_inc(x_4);
 x_362 = l_Lean_Meta_Split_findSplit_x3f_go(x_361, x_2, x_4, x_3);
 if (lean_obj_tag(x_362) == 0)
 {
 lean_object* x_363; lean_object* x_364; lean_object* x_365; lean_object* x_366; lean_object* x_367; lean_object* x_368; uint8_t x_369; 
 lean_dec(x_4);
-lean_dec(x_3);
 x_363 = l_Array_forInUnsafe_loop___at___private_Lean_Meta_Tactic_Split_0__Lean_Meta_Split_generalizeMatchDiscrs_mkNewTarget___spec__4___closed__3;
 x_364 = l_Lean_isTracingEnabledFor___at_Lean_Meta_processPostponed_loop___spec__1(x_363, x_5, x_6, x_7, x_8, x_360);
 x_365 = lean_ctor_get(x_364, 0);
@@ -15644,7 +15629,6 @@ lean_dec(x_7);
 lean_dec(x_6);
 lean_dec(x_5);
 lean_dec(x_4);
-lean_dec(x_3);
 lean_dec(x_1);
 x_386 = lean_ctor_get(x_385, 0);
 lean_inc(x_386);
@@ -15815,7 +15799,6 @@ lean_dec(x_7);
 lean_dec(x_6);
 lean_dec(x_5);
 lean_dec(x_4);
-lean_dec(x_3);
 lean_dec(x_1);
 if (lean_is_scalar(x_393)) {
  x_432 = lean_alloc_ctor(1, 2, 0);
@@ -15836,7 +15819,6 @@ lean_dec(x_7);
 lean_dec(x_6);
 lean_dec(x_5);
 lean_dec(x_4);
-lean_dec(x_3);
 lean_dec(x_1);
 if (lean_is_scalar(x_393)) {
  x_433 = lean_alloc_ctor(1, 2, 0);
@@ -15855,7 +15837,6 @@ lean_object* x_434; lean_object* x_435;
 lean_dec(x_382);
 lean_dec(x_381);
 lean_dec(x_4);
-lean_dec(x_3);
 x_434 = lean_box(0);
 x_435 = l_Lean_Meta_splitIfTarget_x3f(x_1, x_434, x_5, x_6, x_7, x_8, x_360);
 if (lean_obj_tag(x_435) == 0)
@@ -15997,7 +15978,6 @@ lean_object* x_459; lean_object* x_460;
 lean_dec(x_382);
 lean_dec(x_381);
 lean_dec(x_4);
-lean_dec(x_3);
 x_459 = lean_box(0);
 x_460 = l_Lean_Meta_splitIfTarget_x3f(x_1, x_459, x_5, x_6, x_7, x_8, x_360);
 if (lean_obj_tag(x_460) == 0)
@@ -16144,6 +16124,7 @@ x_12 = lean_unbox(x_4);
 lean_dec(x_4);
 x_13 = l_Lean_Meta_splitTarget_x3f_go___lambda__1(x_1, x_2, x_3, x_12, x_5, x_6, x_7, x_8, x_9, x_10, x_11);
 lean_dec(x_6);
+lean_dec(x_5);
 return x_13;
 }
 }
@@ -16154,6 +16135,7 @@ uint8_t x_10; lean_object* x_11;
 x_10 = lean_unbox(x_2);
 lean_dec(x_2);
 x_11 = l_Lean_Meta_splitTarget_x3f_go(x_1, x_10, x_3, x_4, x_5, x_6, x_7, x_8, x_9);
+lean_dec(x_3);
 return x_11;
 }
 }
@@ -16402,6 +16384,7 @@ lean_inc(x_13);
 lean_dec(x_11);
 x_14 = l_Lean_Meta_splitTarget_x3f___lambda__1___closed__1;
 x_15 = l_Lean_Meta_splitTarget_x3f_go(x_1, x_2, x_12, x_14, x_3, x_4, x_5, x_6, x_13);
+lean_dec(x_12);
 return x_15;
 }
 else
@@ -17407,6 +17390,7 @@ x_20 = lean_ctor_get(x_17, 1);
 x_21 = 1;
 x_22 = l_Lean_Meta_splitTarget_x3f___lambda__1___closed__1;
 x_23 = l_Lean_Meta_Split_findSplit_x3f_go(x_12, x_21, x_22, x_19);
+lean_dec(x_19);
 if (lean_obj_tag(x_23) == 0)
 {
 lean_object* x_24; 
@@ -17941,6 +17925,7 @@ lean_dec(x_17);
 x_128 = 1;
 x_129 = l_Lean_Meta_splitTarget_x3f___lambda__1___closed__1;
 x_130 = l_Lean_Meta_Split_findSplit_x3f_go(x_12, x_128, x_129, x_126);
+lean_dec(x_126);
 if (lean_obj_tag(x_130) == 0)
 {
 lean_object* x_131; lean_object* x_132; 
@@ -18384,6 +18369,7 @@ if (lean_is_exclusive(x_204)) {
 x_208 = 1;
 x_209 = l_Lean_Meta_splitTarget_x3f___lambda__1___closed__1;
 x_210 = l_Lean_Meta_Split_findSplit_x3f_go(x_199, x_208, x_209, x_205);
+lean_dec(x_205);
 if (lean_obj_tag(x_210) == 0)
 {
 lean_object* x_211; lean_object* x_212; 
diff --git a/stage0/stdlib/Lean/Meta/Tactic/SplitIf.c b/stage0/stdlib/Lean/Meta/Tactic/SplitIf.c
index 0cd73175ad..c84f073c25 100644
--- a/stage0/stdlib/Lean/Meta/Tactic/SplitIf.c
+++ b/stage0/stdlib/Lean/Meta/Tactic/SplitIf.c
@@ -126,6 +126,7 @@ static lean_object* l___private_Lean_Meta_Tactic_SplitIf_0__Lean_Meta_SplitIf_di
 static lean_object* l_Lean_Meta_simpIfLocalDecl___closed__2;
 LEAN_EXPORT lean_object* l_Lean_Meta_SplitIf_mkDischarge_x3f(uint8_t, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 lean_object* l_Lean_Meta_mkDecide(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
+LEAN_EXPORT lean_object* l___private_Lean_Meta_Tactic_SplitIf_0__Lean_Meta_SplitIf_findIfToSplit_x3f___boxed(lean_object*);
 static uint32_t l_Lean_Meta_SplitIf_initFn____x40_Lean_Meta_Tactic_SplitIf___hyg_5____lambda__1___closed__8;
 uint8_t lean_name_eq(lean_object*, lean_object*);
 lean_object* l_Lean_Name_str___override(lean_object*, lean_object*);
@@ -144,7 +145,6 @@ lean_object* l_Lean_MessageData_ofExpr(lean_object*);
 static lean_object* l_Lean_Meta_simpIfTarget___closed__7;
 static lean_object* l_Lean_LazyInitExtension_get___at_Lean_Meta_SplitIf_getSimpContext___spec__1___closed__1;
 LEAN_EXPORT lean_object* l_Array_findSomeRevM_x3f_find___at___private_Lean_Meta_Tactic_SplitIf_0__Lean_Meta_SplitIf_discharge_x3f___spec__5(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
-lean_object* l_Lean_Expr_FindImpl_findUnsafe_x3f(lean_object*, lean_object*);
 static lean_object* l_Lean_Meta_SplitIf_initFn____x40_Lean_Meta_Tactic_SplitIf___hyg_5____closed__1;
 static lean_object* l_Lean_Meta_initFn____x40_Lean_Meta_Tactic_SplitIf___hyg_1615____closed__3;
 LEAN_EXPORT lean_object* l___private_Lean_Meta_Tactic_SplitIf_0__Lean_Meta_SplitIf_findIfToSplit_x3f(lean_object*);
@@ -198,6 +198,7 @@ lean_object* l_Lean_LocalDecl_toExpr(lean_object*);
 LEAN_EXPORT lean_object* l_Lean_PersistentArray_findSomeRevM_x3f___at___private_Lean_Meta_Tactic_SplitIf_0__Lean_Meta_SplitIf_discharge_x3f___spec__2___boxed(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 static lean_object* l_Lean_Meta_initFn____x40_Lean_Meta_Tactic_SplitIf___hyg_1615____closed__4;
 lean_object* lean_infer_type(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
+lean_object* lean_find_expr(lean_object*, lean_object*);
 static lean_object* l_Lean_Meta_initFn____x40_Lean_Meta_Tactic_SplitIf___hyg_1615____closed__7;
 uint8_t lean_nat_dec_le(lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l___private_Lean_Meta_Tactic_SplitIf_0__Lean_Meta_SplitIf_findIfToSplit_x3f___lambda__1___boxed(lean_object*);
@@ -3673,7 +3674,7 @@ _start:
 {
 lean_object* x_2; lean_object* x_3; 
 x_2 = l___private_Lean_Meta_Tactic_SplitIf_0__Lean_Meta_SplitIf_findIfToSplit_x3f___closed__1;
-x_3 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_2, x_1);
+x_3 = lean_find_expr(x_2, x_1);
 if (lean_obj_tag(x_3) == 0)
 {
 lean_object* x_4; 
@@ -3693,7 +3694,6 @@ x_8 = l_Lean_Expr_getRevArg_x21(x_6, x_7);
 x_9 = l___private_Lean_Meta_Tactic_SplitIf_0__Lean_Meta_SplitIf_findIfToSplit_x3f___closed__3;
 x_10 = l_Lean_Expr_getRevArg_x21(x_6, x_9);
 lean_dec(x_6);
-lean_inc(x_8);
 x_11 = l___private_Lean_Meta_Tactic_SplitIf_0__Lean_Meta_SplitIf_findIfToSplit_x3f(x_8);
 if (lean_obj_tag(x_11) == 0)
 {
@@ -3738,7 +3738,6 @@ x_18 = l_Lean_Expr_getRevArg_x21(x_16, x_17);
 x_19 = l___private_Lean_Meta_Tactic_SplitIf_0__Lean_Meta_SplitIf_findIfToSplit_x3f___closed__3;
 x_20 = l_Lean_Expr_getRevArg_x21(x_16, x_19);
 lean_dec(x_16);
-lean_inc(x_18);
 x_21 = l___private_Lean_Meta_Tactic_SplitIf_0__Lean_Meta_SplitIf_findIfToSplit_x3f(x_18);
 if (lean_obj_tag(x_21) == 0)
 {
@@ -3786,6 +3785,15 @@ x_3 = lean_box(x_2);
 return x_3;
 }
 }
+LEAN_EXPORT lean_object* l___private_Lean_Meta_Tactic_SplitIf_0__Lean_Meta_SplitIf_findIfToSplit_x3f___boxed(lean_object* x_1) {
+_start:
+{
+lean_object* x_2; 
+x_2 = l___private_Lean_Meta_Tactic_SplitIf_0__Lean_Meta_SplitIf_findIfToSplit_x3f(x_1);
+lean_dec(x_1);
+return x_2;
+}
+}
 LEAN_EXPORT lean_object* l_Lean_Meta_SplitIf_splitIfAt_x3f___lambda__1(lean_object* x_1, lean_object* x_2, lean_object* x_3, lean_object* x_4, lean_object* x_5, lean_object* x_6, lean_object* x_7, lean_object* x_8, lean_object* x_9, lean_object* x_10) {
 _start:
 {
@@ -3970,6 +3978,7 @@ lean_object* x_11; lean_object* x_12; lean_object* x_13;
 x_11 = lean_ctor_get(x_9, 0);
 x_12 = lean_ctor_get(x_9, 1);
 x_13 = l___private_Lean_Meta_Tactic_SplitIf_0__Lean_Meta_SplitIf_findIfToSplit_x3f(x_11);
+lean_dec(x_11);
 if (lean_obj_tag(x_13) == 0)
 {
 lean_object* x_14; 
@@ -4033,6 +4042,7 @@ lean_inc(x_28);
 lean_inc(x_27);
 lean_dec(x_9);
 x_29 = l___private_Lean_Meta_Tactic_SplitIf_0__Lean_Meta_SplitIf_findIfToSplit_x3f(x_27);
+lean_dec(x_27);
 if (lean_obj_tag(x_29) == 0)
 {
 lean_object* x_30; lean_object* x_31; 
diff --git a/stage0/stdlib/Lean/PrettyPrinter.c b/stage0/stdlib/Lean/PrettyPrinter.c
index 615285289f..92b7657c74 100644
--- a/stage0/stdlib/Lean/PrettyPrinter.c
+++ b/stage0/stdlib/Lean/PrettyPrinter.c
@@ -4460,6 +4460,7 @@ x_8 = lean_ctor_get(x_7, 0);
 lean_inc(x_8);
 lean_dec(x_7);
 x_9 = l_Lean_Expr_hasSyntheticSorry(x_8);
+lean_dec(x_8);
 if (x_9 == 0)
 {
 size_t x_10; size_t x_11; 
diff --git a/stage0/stdlib/Lean/PrettyPrinter/Delaborator/Basic.c b/stage0/stdlib/Lean/PrettyPrinter/Delaborator/Basic.c
index bb046445d9..34bb406cc0 100644
--- a/stage0/stdlib/Lean/PrettyPrinter/Delaborator/Basic.c
+++ b/stage0/stdlib/Lean/PrettyPrinter/Delaborator/Basic.c
@@ -40,6 +40,7 @@ LEAN_EXPORT lean_object* l_Lean_PrettyPrinter_Delaborator_OmissionReason_toCtorI
 LEAN_EXPORT lean_object* l_Lean_PrettyPrinter_delabCore___rarg___lambda__3___boxed(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 static lean_object* l_Lean_PrettyPrinter_Delaborator_mkDelabAttribute___closed__9;
 LEAN_EXPORT lean_object* l_Lean_PrettyPrinter_Delaborator_getUnusedName_bodyUsesSuggestion___boxed(lean_object*, lean_object*, lean_object*);
+LEAN_EXPORT lean_object* l_Lean_PrettyPrinter_Delaborator_getUnusedName___boxed(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_PrettyPrinter_Delaborator_SubExpr_getExpr___at_Lean_PrettyPrinter_Delaborator_getExprKind___spec__1(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_PrettyPrinter_Delaborator_SubExpr_getPos___at_Lean_PrettyPrinter_Delaborator_getOptionsAtCurrPos___spec__1(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 static lean_object* l_Lean_PrettyPrinter_Delaborator_omission___closed__5;
@@ -291,7 +292,6 @@ static lean_object* l_Lean_PrettyPrinter_Delaborator_getExprKind___closed__7;
 LEAN_EXPORT lean_object* l_Lean_PrettyPrinter_delabCore(lean_object*);
 LEAN_EXPORT lean_object* l_Lean_PrettyPrinter_Delaborator_mkAnnotatedIdent(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 lean_object* l_Lean_Core_transform___at_Lean_Core_betaReduce___spec__1(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
-lean_object* l_Lean_Expr_FindImpl_findUnsafe_x3f(lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_PrettyPrinter_Delaborator_instAlternativeDelabM___lambda__1(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_PrettyPrinter_Delaborator_delabFailureId;
 LEAN_EXPORT lean_object* l_Lean_Meta_withLocalDecl___at_Lean_PrettyPrinter_Delaborator_withBindingBodyUnusedName___spec__3___rarg___boxed(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
@@ -409,6 +409,7 @@ LEAN_EXPORT lean_object* l_Lean_PrettyPrinter_Delaborator_withBindingBodyUnusedN
 uint8_t l_Lean_Expr_isMData(lean_object*);
 LEAN_EXPORT lean_object* l_Lean_PrettyPrinter_Delaborator_SubExpr_nextExtraPos___at_Lean_PrettyPrinter_Delaborator_mkAnnotatedIdent___spec__1___boxed(lean_object*);
 lean_object* lean_infer_type(lean_object*, lean_object*, lean_object*, lean_object*, lean_object*, lean_object*);
+lean_object* lean_find_expr(lean_object*, lean_object*);
 uint8_t lean_nat_dec_le(lean_object*, lean_object*);
 static lean_object* l_Lean_PrettyPrinter_Delaborator_omission___closed__3;
 static lean_object* l_Lean_PrettyPrinter_Delaborator_getExprKind___closed__6;
@@ -6351,7 +6352,8 @@ lean_object* x_4; lean_object* x_5;
 x_4 = lean_alloc_closure((void*)(l_Lean_PrettyPrinter_Delaborator_getUnusedName_bodyUsesSuggestion___lambda__1___boxed), 3, 2);
 lean_closure_set(x_4, 0, x_2);
 lean_closure_set(x_4, 1, x_3);
-x_5 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_4, x_1);
+x_5 = lean_find_expr(x_4, x_1);
+lean_dec(x_4);
 if (lean_obj_tag(x_5) == 0)
 {
 uint8_t x_6; 
@@ -6382,6 +6384,7 @@ _start:
 {
 uint8_t x_4; lean_object* x_5; 
 x_4 = l_Lean_PrettyPrinter_Delaborator_getUnusedName_bodyUsesSuggestion(x_1, x_2, x_3);
+lean_dec(x_1);
 x_5 = lean_box(x_4);
 return x_5;
 }
@@ -6443,7 +6446,6 @@ lean_dec(x_6);
 lean_dec(x_5);
 lean_dec(x_4);
 lean_dec(x_3);
-lean_dec(x_2);
 x_14 = lean_alloc_ctor(0, 2, 0);
 lean_ctor_set(x_14, 0, x_12);
 lean_ctor_set(x_14, 1, x_9);
@@ -6464,7 +6466,6 @@ lean_dec(x_17);
 if (x_18 == 0)
 {
 uint8_t x_19; 
-lean_dec(x_2);
 x_19 = !lean_is_exclusive(x_16);
 if (x_19 == 0)
 {
@@ -6553,7 +6554,6 @@ else
 uint8_t x_34; 
 lean_dec(x_12);
 lean_dec(x_11);
-lean_dec(x_2);
 x_34 = !lean_is_exclusive(x_16);
 if (x_34 == 0)
 {
@@ -6593,7 +6593,6 @@ lean_dec(x_6);
 lean_dec(x_5);
 lean_dec(x_4);
 lean_dec(x_3);
-lean_dec(x_2);
 x_41 = lean_alloc_ctor(0, 2, 0);
 lean_ctor_set(x_41, 0, x_39);
 lean_ctor_set(x_41, 1, x_9);
@@ -6614,7 +6613,6 @@ lean_dec(x_44);
 if (x_45 == 0)
 {
 uint8_t x_46; 
-lean_dec(x_2);
 x_46 = !lean_is_exclusive(x_43);
 if (x_46 == 0)
 {
@@ -6700,7 +6698,6 @@ else
 {
 uint8_t x_61; 
 lean_dec(x_38);
-lean_dec(x_2);
 x_61 = !lean_is_exclusive(x_43);
 if (x_61 == 0)
 {
@@ -6724,6 +6721,15 @@ return x_64;
 }
 }
 }
+LEAN_EXPORT lean_object* l_Lean_PrettyPrinter_Delaborator_getUnusedName___boxed(lean_object* x_1, lean_object* x_2, lean_object* x_3, lean_object* x_4, lean_object* x_5, lean_object* x_6, lean_object* x_7, lean_object* x_8, lean_object* x_9) {
+_start:
+{
+lean_object* x_10; 
+x_10 = l_Lean_PrettyPrinter_Delaborator_getUnusedName(x_1, x_2, x_3, x_4, x_5, x_6, x_7, x_8, x_9);
+lean_dec(x_2);
+return x_10;
+}
+}
 LEAN_EXPORT lean_object* l_Lean_PrettyPrinter_Delaborator_SubExpr_nextExtraPos___at_Lean_PrettyPrinter_Delaborator_mkAnnotatedIdent___spec__1___rarg(lean_object* x_1, lean_object* x_2, lean_object* x_3, lean_object* x_4, lean_object* x_5, lean_object* x_6) {
 _start:
 {
@@ -7149,6 +7155,7 @@ lean_inc(x_4);
 lean_inc(x_3);
 lean_inc(x_2);
 x_17 = l_Lean_PrettyPrinter_Delaborator_getUnusedName(x_15, x_16, x_2, x_3, x_4, x_5, x_6, x_7, x_14);
+lean_dec(x_16);
 if (lean_obj_tag(x_17) == 0)
 {
 lean_object* x_18; lean_object* x_19; lean_object* x_20; lean_object* x_21; 
diff --git a/stage0/stdlib/Lean/PrettyPrinter/Delaborator/Builtins.c b/stage0/stdlib/Lean/PrettyPrinter/Delaborator/Builtins.c
index 502f3b2f99..84c433e5b8 100644
--- a/stage0/stdlib/Lean/PrettyPrinter/Delaborator/Builtins.c
+++ b/stage0/stdlib/Lean/PrettyPrinter/Delaborator/Builtins.c
@@ -23079,7 +23079,6 @@ lean_inc(x_8);
 lean_inc(x_7);
 lean_inc(x_6);
 lean_inc(x_5);
-lean_inc(x_2);
 x_21 = l_Lean_PrettyPrinter_Delaborator_getUnusedName(x_20, x_2, x_5, x_6, x_7, x_8, x_9, x_10, x_11);
 if (lean_obj_tag(x_21) == 0)
 {
@@ -28735,6 +28734,7 @@ lean_inc(x_4);
 lean_inc(x_3);
 lean_inc(x_2);
 x_17 = l_Lean_PrettyPrinter_Delaborator_getUnusedName(x_15, x_16, x_2, x_3, x_4, x_5, x_6, x_7, x_13);
+lean_dec(x_16);
 if (lean_obj_tag(x_17) == 0)
 {
 lean_object* x_18; lean_object* x_19; lean_object* x_20; lean_object* x_21; 
@@ -34916,7 +34916,6 @@ lean_inc(x_4);
 lean_inc(x_3);
 lean_inc(x_2);
 lean_inc(x_1);
-lean_inc(x_15);
 x_16 = l_Lean_PrettyPrinter_Delaborator_getUnusedName(x_12, x_15, x_1, x_2, x_3, x_4, x_5, x_6, x_10);
 if (lean_obj_tag(x_16) == 0)
 {
@@ -43777,7 +43776,6 @@ lean_inc(x_4);
 lean_inc(x_3);
 lean_inc(x_2);
 lean_inc(x_1);
-lean_inc(x_66);
 x_67 = l_Lean_PrettyPrinter_Delaborator_getUnusedName(x_63, x_66, x_1, x_2, x_3, x_4, x_5, x_6, x_62);
 if (lean_obj_tag(x_67) == 0)
 {
@@ -44265,7 +44263,6 @@ lean_inc(x_4);
 lean_inc(x_3);
 lean_inc(x_2);
 lean_inc(x_1);
-lean_inc(x_174);
 x_175 = l_Lean_PrettyPrinter_Delaborator_getUnusedName(x_171, x_174, x_1, x_2, x_3, x_4, x_5, x_6, x_170);
 if (lean_obj_tag(x_175) == 0)
 {
diff --git a/stage0/stdlib/Lean/Server/InfoUtils.c b/stage0/stdlib/Lean/Server/InfoUtils.c
index 5ebd442e6e..33c3ef168d 100644
--- a/stage0/stdlib/Lean/Server/InfoUtils.c
+++ b/stage0/stdlib/Lean/Server/InfoUtils.c
@@ -18291,6 +18291,7 @@ if (x_18 == 0)
 lean_object* x_19; uint8_t x_20; lean_object* x_21; 
 x_19 = lean_ctor_get(x_17, 0);
 x_20 = l_Lean_Expr_hasSorry(x_19);
+lean_dec(x_19);
 x_21 = lean_box(x_20);
 lean_ctor_set(x_17, 0, x_21);
 return x_17;
@@ -18304,6 +18305,7 @@ lean_inc(x_23);
 lean_inc(x_22);
 lean_dec(x_17);
 x_24 = l_Lean_Expr_hasSorry(x_22);
+lean_dec(x_22);
 x_25 = lean_box(x_24);
 x_26 = lean_alloc_ctor(0, 2, 0);
 lean_ctor_set(x_26, 0, x_25);
@@ -18460,6 +18462,7 @@ if (x_55 == 0)
 lean_object* x_56; uint8_t x_57; lean_object* x_58; 
 x_56 = lean_ctor_get(x_54, 0);
 x_57 = l_Lean_Expr_hasSorry(x_56);
+lean_dec(x_56);
 x_58 = lean_box(x_57);
 lean_ctor_set(x_54, 0, x_58);
 return x_54;
@@ -18473,6 +18476,7 @@ lean_inc(x_60);
 lean_inc(x_59);
 lean_dec(x_54);
 x_61 = l_Lean_Expr_hasSorry(x_59);
+lean_dec(x_59);
 x_62 = lean_box(x_61);
 x_63 = lean_alloc_ctor(0, 2, 0);
 lean_ctor_set(x_63, 0, x_62);
diff --git a/stage0/stdlib/Lean/Util/FindExpr.c b/stage0/stdlib/Lean/Util/FindExpr.c
index 26abeb2a2b..19cb7e9d71 100644
--- a/stage0/stdlib/Lean/Util/FindExpr.c
+++ b/stage0/stdlib/Lean/Util/FindExpr.c
@@ -15,1420 +15,25 @@ extern "C" {
 #endif
 LEAN_EXPORT lean_object* l_Lean_Expr_FindStep_toCtorIdx(uint8_t);
 LEAN_EXPORT lean_object* l_Lean_Expr_FindStep_noConfusion___rarg(uint8_t, uint8_t, lean_object*);
-LEAN_EXPORT lean_object* l_Lean_Expr_FindImpl_findM_x3f(lean_object*, lean_object*, lean_object*);
-uint64_t lean_uint64_mix_hash(uint64_t, uint64_t);
-size_t lean_hashset_mk_idx(lean_object*, uint64_t);
 LEAN_EXPORT lean_object* l_Lean_Expr_occurs___boxed(lean_object*, lean_object*);
-lean_object* l_Lean_mkHashSetImp___rarg(lean_object*);
 LEAN_EXPORT lean_object* l_Lean_Expr_FindStep_toCtorIdx___boxed(lean_object*);
-lean_object* lean_mk_array(lean_object*, lean_object*);
-uint8_t lean_usize_dec_eq(size_t, size_t);
-LEAN_EXPORT uint8_t l_Lean_HashSetImp_contains___at_Lean_Expr_FindImpl_checkVisited___spec__8(lean_object*, lean_object*);
-lean_object* lean_array_fget(lean_object*, lean_object*);
-lean_object* lean_array_fset(lean_object*, lean_object*, lean_object*);
-LEAN_EXPORT lean_object* l_Lean_Expr_FindImpl_findM_x3f_visit(lean_object*, lean_object*, lean_object*);
+LEAN_EXPORT lean_object* l_Lean_Expr_findExt_x3f(lean_object*, lean_object*);
+LEAN_EXPORT lean_object* l_Lean_Expr_findExt_x3f___boxed(lean_object*, lean_object*);
 static lean_object* l_Lean_Expr_FindStep_noConfusion___rarg___closed__1;
-static lean_object* l_Lean_Expr_FindImpl_findUnsafe_x3f___closed__1;
-size_t lean_ptr_addr(lean_object*);
 LEAN_EXPORT lean_object* l_Lean_Expr_findExtImpl_x3f___boxed(lean_object*, lean_object*);
+LEAN_EXPORT lean_object* l_Lean_Expr_find_x3f___boxed(lean_object*, lean_object*);
 uint8_t lean_expr_eqv(lean_object*, lean_object*);
-uint64_t lean_usize_to_uint64(size_t);
 LEAN_EXPORT lean_object* l_Lean_Expr_FindStep_noConfusion___rarg___lambda__1___boxed(lean_object*);
-LEAN_EXPORT lean_object* l_List_foldl___at_Lean_Expr_FindImpl_checkVisited___spec__5(lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_Expr_findImpl_x3f___boxed(lean_object*, lean_object*);
-LEAN_EXPORT lean_object* l_Lean_Expr_FindImpl_checkVisited___lambda__1___boxed(lean_object*, lean_object*, lean_object*);
-LEAN_EXPORT lean_object* l_Lean_HashSetImp_moveEntries___at_Lean_Expr_FindImpl_checkVisited___spec__4(lean_object*, lean_object*, lean_object*);
-LEAN_EXPORT uint8_t l_List_elem___at_Lean_Expr_FindImpl_checkVisited___spec__2(lean_object*, lean_object*);
-LEAN_EXPORT lean_object* l_Lean_Expr_FindExtImpl_findUnsafe_x3f(lean_object*, lean_object*);
-LEAN_EXPORT lean_object* l_Lean_HashSetImp_expand___at_Lean_Expr_FindImpl_checkVisited___spec__3(lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_Expr_FindStep_noConfusion(lean_object*);
 lean_object* lean_find_ext_expr(lean_object*, lean_object*);
-LEAN_EXPORT lean_object* l_Lean_Expr_FindImpl_findUnsafe_x3f(lean_object*, lean_object*);
-LEAN_EXPORT lean_object* l_Lean_Expr_FindExtImpl_findM_x3f_visit(lean_object*, lean_object*, lean_object*);
-uint8_t lean_nat_dec_lt(lean_object*, lean_object*);
-LEAN_EXPORT lean_object* l_Lean_HashSetImp_insert___at_Lean_Expr_FindImpl_checkVisited___spec__1(lean_object*, lean_object*);
-lean_object* lean_nat_mul(lean_object*, lean_object*);
-LEAN_EXPORT lean_object* l_Lean_Expr_FindExtImpl_findM_x3f(lean_object*, lean_object*, lean_object*);
-LEAN_EXPORT lean_object* l_List_replace___at_Lean_Expr_FindImpl_checkVisited___spec__7___boxed(lean_object*, lean_object*, lean_object*);
-LEAN_EXPORT lean_object* l_List_replace___at_Lean_Expr_FindImpl_checkVisited___spec__7(lean_object*, lean_object*, lean_object*);
+LEAN_EXPORT lean_object* l_Lean_Expr_find_x3f(lean_object*, lean_object*);
 LEAN_EXPORT uint8_t l_Lean_Expr_occurs(lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_Expr_FindStep_noConfusion___rarg___boxed(lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_Expr_occurs___lambda__1___boxed(lean_object*, lean_object*);
-lean_object* lean_array_uget(lean_object*, size_t);
-LEAN_EXPORT lean_object* l_List_elem___at_Lean_Expr_FindImpl_checkVisited___spec__2___boxed(lean_object*, lean_object*);
-LEAN_EXPORT lean_object* l_Lean_Expr_FindImpl_checkVisited___lambda__1(lean_object*, lean_object*, lean_object*);
-LEAN_EXPORT lean_object* l_Lean_Expr_FindExtImpl_findM_x3f_visitApp(lean_object*, lean_object*, lean_object*);
-lean_object* lean_array_get_size(lean_object*);
 lean_object* lean_find_expr(lean_object*, lean_object*);
-uint8_t lean_nat_dec_le(lean_object*, lean_object*);
-lean_object* lean_nat_add(lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_Expr_FindStep_noConfusion___rarg___lambda__1(lean_object*);
-LEAN_EXPORT lean_object* l_Lean_HashSetImp_contains___at_Lean_Expr_FindImpl_checkVisited___spec__8___boxed(lean_object*, lean_object*);
-LEAN_EXPORT lean_object* l_List_foldl___at_Lean_Expr_FindImpl_checkVisited___spec__5___at_Lean_Expr_FindImpl_checkVisited___spec__6(lean_object*, lean_object*);
-static lean_object* l_Lean_Expr_FindImpl_checkVisited___lambda__1___closed__1;
-LEAN_EXPORT lean_object* l_Lean_Expr_FindImpl_checkVisited(lean_object*, lean_object*);
 LEAN_EXPORT uint8_t l_Lean_Expr_occurs___lambda__1(lean_object*, lean_object*);
-lean_object* lean_array_uset(lean_object*, size_t, lean_object*);
-LEAN_EXPORT uint8_t l_List_elem___at_Lean_Expr_FindImpl_checkVisited___spec__2(lean_object* x_1, lean_object* x_2) {
-_start:
-{
-if (lean_obj_tag(x_2) == 0)
-{
-uint8_t x_3; 
-x_3 = 0;
-return x_3;
-}
-else
-{
-lean_object* x_4; lean_object* x_5; size_t x_6; size_t x_7; uint8_t x_8; 
-x_4 = lean_ctor_get(x_2, 0);
-x_5 = lean_ctor_get(x_2, 1);
-x_6 = lean_ptr_addr(x_1);
-x_7 = lean_ptr_addr(x_4);
-x_8 = lean_usize_dec_eq(x_6, x_7);
-if (x_8 == 0)
-{
-x_2 = x_5;
-goto _start;
-}
-else
-{
-uint8_t x_10; 
-x_10 = 1;
-return x_10;
-}
-}
-}
-}
-LEAN_EXPORT lean_object* l_List_foldl___at_Lean_Expr_FindImpl_checkVisited___spec__5(lean_object* x_1, lean_object* x_2, lean_object* x_3) {
-_start:
-{
-if (lean_obj_tag(x_3) == 0)
-{
-lean_dec(x_1);
-return x_2;
-}
-else
-{
-uint8_t x_4; 
-x_4 = !lean_is_exclusive(x_3);
-if (x_4 == 0)
-{
-lean_object* x_5; lean_object* x_6; lean_object* x_7; lean_object* x_8; uint64_t x_9; size_t x_10; lean_object* x_11; lean_object* x_12; 
-x_5 = lean_ctor_get(x_3, 0);
-x_6 = lean_ctor_get(x_3, 1);
-x_7 = lean_array_get_size(x_2);
-lean_inc(x_1);
-lean_inc(x_5);
-x_8 = lean_apply_1(x_1, x_5);
-x_9 = lean_unbox_uint64(x_8);
-lean_dec(x_8);
-x_10 = lean_hashset_mk_idx(x_7, x_9);
-x_11 = lean_array_uget(x_2, x_10);
-lean_ctor_set(x_3, 1, x_11);
-x_12 = lean_array_uset(x_2, x_10, x_3);
-x_2 = x_12;
-x_3 = x_6;
-goto _start;
-}
-else
-{
-lean_object* x_14; lean_object* x_15; lean_object* x_16; lean_object* x_17; uint64_t x_18; size_t x_19; lean_object* x_20; lean_object* x_21; lean_object* x_22; 
-x_14 = lean_ctor_get(x_3, 0);
-x_15 = lean_ctor_get(x_3, 1);
-lean_inc(x_15);
-lean_inc(x_14);
-lean_dec(x_3);
-x_16 = lean_array_get_size(x_2);
-lean_inc(x_1);
-lean_inc(x_14);
-x_17 = lean_apply_1(x_1, x_14);
-x_18 = lean_unbox_uint64(x_17);
-lean_dec(x_17);
-x_19 = lean_hashset_mk_idx(x_16, x_18);
-x_20 = lean_array_uget(x_2, x_19);
-x_21 = lean_alloc_ctor(1, 2, 0);
-lean_ctor_set(x_21, 0, x_14);
-lean_ctor_set(x_21, 1, x_20);
-x_22 = lean_array_uset(x_2, x_19, x_21);
-x_2 = x_22;
-x_3 = x_15;
-goto _start;
-}
-}
-}
-}
-LEAN_EXPORT lean_object* l_List_foldl___at_Lean_Expr_FindImpl_checkVisited___spec__5___at_Lean_Expr_FindImpl_checkVisited___spec__6(lean_object* x_1, lean_object* x_2) {
-_start:
-{
-if (lean_obj_tag(x_2) == 0)
-{
-return x_1;
-}
-else
-{
-uint8_t x_3; 
-x_3 = !lean_is_exclusive(x_2);
-if (x_3 == 0)
-{
-lean_object* x_4; lean_object* x_5; lean_object* x_6; size_t x_7; uint64_t x_8; uint64_t x_9; uint64_t x_10; size_t x_11; lean_object* x_12; lean_object* x_13; 
-x_4 = lean_ctor_get(x_2, 0);
-x_5 = lean_ctor_get(x_2, 1);
-x_6 = lean_array_get_size(x_1);
-x_7 = lean_ptr_addr(x_4);
-x_8 = lean_usize_to_uint64(x_7);
-x_9 = 11;
-x_10 = lean_uint64_mix_hash(x_8, x_9);
-x_11 = lean_hashset_mk_idx(x_6, x_10);
-x_12 = lean_array_uget(x_1, x_11);
-lean_ctor_set(x_2, 1, x_12);
-x_13 = lean_array_uset(x_1, x_11, x_2);
-x_1 = x_13;
-x_2 = x_5;
-goto _start;
-}
-else
-{
-lean_object* x_15; lean_object* x_16; lean_object* x_17; size_t x_18; uint64_t x_19; uint64_t x_20; uint64_t x_21; size_t x_22; lean_object* x_23; lean_object* x_24; lean_object* x_25; 
-x_15 = lean_ctor_get(x_2, 0);
-x_16 = lean_ctor_get(x_2, 1);
-lean_inc(x_16);
-lean_inc(x_15);
-lean_dec(x_2);
-x_17 = lean_array_get_size(x_1);
-x_18 = lean_ptr_addr(x_15);
-x_19 = lean_usize_to_uint64(x_18);
-x_20 = 11;
-x_21 = lean_uint64_mix_hash(x_19, x_20);
-x_22 = lean_hashset_mk_idx(x_17, x_21);
-x_23 = lean_array_uget(x_1, x_22);
-x_24 = lean_alloc_ctor(1, 2, 0);
-lean_ctor_set(x_24, 0, x_15);
-lean_ctor_set(x_24, 1, x_23);
-x_25 = lean_array_uset(x_1, x_22, x_24);
-x_1 = x_25;
-x_2 = x_16;
-goto _start;
-}
-}
-}
-}
-LEAN_EXPORT lean_object* l_Lean_HashSetImp_moveEntries___at_Lean_Expr_FindImpl_checkVisited___spec__4(lean_object* x_1, lean_object* x_2, lean_object* x_3) {
-_start:
-{
-lean_object* x_4; uint8_t x_5; 
-x_4 = lean_array_get_size(x_2);
-x_5 = lean_nat_dec_lt(x_1, x_4);
-lean_dec(x_4);
-if (x_5 == 0)
-{
-lean_dec(x_2);
-lean_dec(x_1);
-return x_3;
-}
-else
-{
-lean_object* x_6; lean_object* x_7; lean_object* x_8; lean_object* x_9; lean_object* x_10; lean_object* x_11; 
-x_6 = lean_array_fget(x_2, x_1);
-x_7 = lean_box(0);
-x_8 = lean_array_fset(x_2, x_1, x_7);
-x_9 = l_List_foldl___at_Lean_Expr_FindImpl_checkVisited___spec__5___at_Lean_Expr_FindImpl_checkVisited___spec__6(x_3, x_6);
-x_10 = lean_unsigned_to_nat(1u);
-x_11 = lean_nat_add(x_1, x_10);
-lean_dec(x_1);
-x_1 = x_11;
-x_2 = x_8;
-x_3 = x_9;
-goto _start;
-}
-}
-}
-LEAN_EXPORT lean_object* l_Lean_HashSetImp_expand___at_Lean_Expr_FindImpl_checkVisited___spec__3(lean_object* x_1, lean_object* x_2) {
-_start:
-{
-lean_object* x_3; lean_object* x_4; lean_object* x_5; lean_object* x_6; lean_object* x_7; lean_object* x_8; lean_object* x_9; lean_object* x_10; 
-x_3 = lean_array_get_size(x_2);
-x_4 = lean_unsigned_to_nat(2u);
-x_5 = lean_nat_mul(x_3, x_4);
-lean_dec(x_3);
-x_6 = lean_box(0);
-x_7 = lean_mk_array(x_5, x_6);
-x_8 = lean_unsigned_to_nat(0u);
-x_9 = l_Lean_HashSetImp_moveEntries___at_Lean_Expr_FindImpl_checkVisited___spec__4(x_8, x_2, x_7);
-x_10 = lean_alloc_ctor(0, 2, 0);
-lean_ctor_set(x_10, 0, x_1);
-lean_ctor_set(x_10, 1, x_9);
-return x_10;
-}
-}
-LEAN_EXPORT lean_object* l_List_replace___at_Lean_Expr_FindImpl_checkVisited___spec__7(lean_object* x_1, lean_object* x_2, lean_object* x_3) {
-_start:
-{
-if (lean_obj_tag(x_1) == 0)
-{
-lean_object* x_4; 
-lean_dec(x_3);
-x_4 = lean_box(0);
-return x_4;
-}
-else
-{
-uint8_t x_5; 
-x_5 = !lean_is_exclusive(x_1);
-if (x_5 == 0)
-{
-lean_object* x_6; lean_object* x_7; size_t x_8; size_t x_9; uint8_t x_10; 
-x_6 = lean_ctor_get(x_1, 0);
-x_7 = lean_ctor_get(x_1, 1);
-x_8 = lean_ptr_addr(x_2);
-x_9 = lean_ptr_addr(x_6);
-x_10 = lean_usize_dec_eq(x_8, x_9);
-if (x_10 == 0)
-{
-lean_object* x_11; 
-x_11 = l_List_replace___at_Lean_Expr_FindImpl_checkVisited___spec__7(x_7, x_2, x_3);
-lean_ctor_set(x_1, 1, x_11);
-return x_1;
-}
-else
-{
-lean_dec(x_6);
-lean_ctor_set(x_1, 0, x_3);
-return x_1;
-}
-}
-else
-{
-lean_object* x_12; lean_object* x_13; size_t x_14; size_t x_15; uint8_t x_16; 
-x_12 = lean_ctor_get(x_1, 0);
-x_13 = lean_ctor_get(x_1, 1);
-lean_inc(x_13);
-lean_inc(x_12);
-lean_dec(x_1);
-x_14 = lean_ptr_addr(x_2);
-x_15 = lean_ptr_addr(x_12);
-x_16 = lean_usize_dec_eq(x_14, x_15);
-if (x_16 == 0)
-{
-lean_object* x_17; lean_object* x_18; 
-x_17 = l_List_replace___at_Lean_Expr_FindImpl_checkVisited___spec__7(x_13, x_2, x_3);
-x_18 = lean_alloc_ctor(1, 2, 0);
-lean_ctor_set(x_18, 0, x_12);
-lean_ctor_set(x_18, 1, x_17);
-return x_18;
-}
-else
-{
-lean_object* x_19; 
-lean_dec(x_12);
-x_19 = lean_alloc_ctor(1, 2, 0);
-lean_ctor_set(x_19, 0, x_3);
-lean_ctor_set(x_19, 1, x_13);
-return x_19;
-}
-}
-}
-}
-}
-LEAN_EXPORT lean_object* l_Lean_HashSetImp_insert___at_Lean_Expr_FindImpl_checkVisited___spec__1(lean_object* x_1, lean_object* x_2) {
-_start:
-{
-uint8_t x_3; 
-x_3 = !lean_is_exclusive(x_1);
-if (x_3 == 0)
-{
-lean_object* x_4; lean_object* x_5; lean_object* x_6; size_t x_7; uint64_t x_8; uint64_t x_9; uint64_t x_10; size_t x_11; lean_object* x_12; uint8_t x_13; 
-x_4 = lean_ctor_get(x_1, 0);
-x_5 = lean_ctor_get(x_1, 1);
-x_6 = lean_array_get_size(x_5);
-x_7 = lean_ptr_addr(x_2);
-x_8 = lean_usize_to_uint64(x_7);
-x_9 = 11;
-x_10 = lean_uint64_mix_hash(x_8, x_9);
-lean_inc(x_6);
-x_11 = lean_hashset_mk_idx(x_6, x_10);
-x_12 = lean_array_uget(x_5, x_11);
-x_13 = l_List_elem___at_Lean_Expr_FindImpl_checkVisited___spec__2(x_2, x_12);
-if (x_13 == 0)
-{
-lean_object* x_14; lean_object* x_15; lean_object* x_16; lean_object* x_17; uint8_t x_18; 
-x_14 = lean_unsigned_to_nat(1u);
-x_15 = lean_nat_add(x_4, x_14);
-lean_dec(x_4);
-x_16 = lean_alloc_ctor(1, 2, 0);
-lean_ctor_set(x_16, 0, x_2);
-lean_ctor_set(x_16, 1, x_12);
-x_17 = lean_array_uset(x_5, x_11, x_16);
-x_18 = lean_nat_dec_le(x_15, x_6);
-lean_dec(x_6);
-if (x_18 == 0)
-{
-lean_object* x_19; 
-lean_free_object(x_1);
-x_19 = l_Lean_HashSetImp_expand___at_Lean_Expr_FindImpl_checkVisited___spec__3(x_15, x_17);
-return x_19;
-}
-else
-{
-lean_ctor_set(x_1, 1, x_17);
-lean_ctor_set(x_1, 0, x_15);
-return x_1;
-}
-}
-else
-{
-lean_object* x_20; lean_object* x_21; lean_object* x_22; lean_object* x_23; 
-lean_dec(x_6);
-x_20 = lean_box(0);
-x_21 = lean_array_uset(x_5, x_11, x_20);
-lean_inc(x_2);
-x_22 = l_List_replace___at_Lean_Expr_FindImpl_checkVisited___spec__7(x_12, x_2, x_2);
-lean_dec(x_2);
-x_23 = lean_array_uset(x_21, x_11, x_22);
-lean_ctor_set(x_1, 1, x_23);
-return x_1;
-}
-}
-else
-{
-lean_object* x_24; lean_object* x_25; lean_object* x_26; size_t x_27; uint64_t x_28; uint64_t x_29; uint64_t x_30; size_t x_31; lean_object* x_32; uint8_t x_33; 
-x_24 = lean_ctor_get(x_1, 0);
-x_25 = lean_ctor_get(x_1, 1);
-lean_inc(x_25);
-lean_inc(x_24);
-lean_dec(x_1);
-x_26 = lean_array_get_size(x_25);
-x_27 = lean_ptr_addr(x_2);
-x_28 = lean_usize_to_uint64(x_27);
-x_29 = 11;
-x_30 = lean_uint64_mix_hash(x_28, x_29);
-lean_inc(x_26);
-x_31 = lean_hashset_mk_idx(x_26, x_30);
-x_32 = lean_array_uget(x_25, x_31);
-x_33 = l_List_elem___at_Lean_Expr_FindImpl_checkVisited___spec__2(x_2, x_32);
-if (x_33 == 0)
-{
-lean_object* x_34; lean_object* x_35; lean_object* x_36; lean_object* x_37; uint8_t x_38; 
-x_34 = lean_unsigned_to_nat(1u);
-x_35 = lean_nat_add(x_24, x_34);
-lean_dec(x_24);
-x_36 = lean_alloc_ctor(1, 2, 0);
-lean_ctor_set(x_36, 0, x_2);
-lean_ctor_set(x_36, 1, x_32);
-x_37 = lean_array_uset(x_25, x_31, x_36);
-x_38 = lean_nat_dec_le(x_35, x_26);
-lean_dec(x_26);
-if (x_38 == 0)
-{
-lean_object* x_39; 
-x_39 = l_Lean_HashSetImp_expand___at_Lean_Expr_FindImpl_checkVisited___spec__3(x_35, x_37);
-return x_39;
-}
-else
-{
-lean_object* x_40; 
-x_40 = lean_alloc_ctor(0, 2, 0);
-lean_ctor_set(x_40, 0, x_35);
-lean_ctor_set(x_40, 1, x_37);
-return x_40;
-}
-}
-else
-{
-lean_object* x_41; lean_object* x_42; lean_object* x_43; lean_object* x_44; lean_object* x_45; 
-lean_dec(x_26);
-x_41 = lean_box(0);
-x_42 = lean_array_uset(x_25, x_31, x_41);
-lean_inc(x_2);
-x_43 = l_List_replace___at_Lean_Expr_FindImpl_checkVisited___spec__7(x_32, x_2, x_2);
-lean_dec(x_2);
-x_44 = lean_array_uset(x_42, x_31, x_43);
-x_45 = lean_alloc_ctor(0, 2, 0);
-lean_ctor_set(x_45, 0, x_24);
-lean_ctor_set(x_45, 1, x_44);
-return x_45;
-}
-}
-}
-}
-LEAN_EXPORT uint8_t l_Lean_HashSetImp_contains___at_Lean_Expr_FindImpl_checkVisited___spec__8(lean_object* x_1, lean_object* x_2) {
-_start:
-{
-lean_object* x_3; lean_object* x_4; size_t x_5; uint64_t x_6; uint64_t x_7; uint64_t x_8; size_t x_9; lean_object* x_10; uint8_t x_11; 
-x_3 = lean_ctor_get(x_1, 1);
-x_4 = lean_array_get_size(x_3);
-x_5 = lean_ptr_addr(x_2);
-x_6 = lean_usize_to_uint64(x_5);
-x_7 = 11;
-x_8 = lean_uint64_mix_hash(x_6, x_7);
-x_9 = lean_hashset_mk_idx(x_4, x_8);
-x_10 = lean_array_uget(x_3, x_9);
-x_11 = l_List_elem___at_Lean_Expr_FindImpl_checkVisited___spec__2(x_2, x_10);
-lean_dec(x_10);
-return x_11;
-}
-}
-static lean_object* _init_l_Lean_Expr_FindImpl_checkVisited___lambda__1___closed__1() {
-_start:
-{
-lean_object* x_1; lean_object* x_2; 
-x_1 = lean_box(0);
-x_2 = lean_alloc_ctor(1, 1, 0);
-lean_ctor_set(x_2, 0, x_1);
-return x_2;
-}
-}
-LEAN_EXPORT lean_object* l_Lean_Expr_FindImpl_checkVisited___lambda__1(lean_object* x_1, lean_object* x_2, lean_object* x_3) {
-_start:
-{
-lean_object* x_4; lean_object* x_5; lean_object* x_6; 
-x_4 = l_Lean_HashSetImp_insert___at_Lean_Expr_FindImpl_checkVisited___spec__1(x_3, x_1);
-x_5 = l_Lean_Expr_FindImpl_checkVisited___lambda__1___closed__1;
-x_6 = lean_alloc_ctor(0, 2, 0);
-lean_ctor_set(x_6, 0, x_5);
-lean_ctor_set(x_6, 1, x_4);
-return x_6;
-}
-}
-LEAN_EXPORT lean_object* l_Lean_Expr_FindImpl_checkVisited(lean_object* x_1, lean_object* x_2) {
-_start:
-{
-uint8_t x_3; 
-x_3 = l_Lean_HashSetImp_contains___at_Lean_Expr_FindImpl_checkVisited___spec__8(x_2, x_1);
-if (x_3 == 0)
-{
-lean_object* x_4; lean_object* x_5; 
-x_4 = lean_box(0);
-x_5 = l_Lean_Expr_FindImpl_checkVisited___lambda__1(x_1, x_4, x_2);
-return x_5;
-}
-else
-{
-lean_object* x_6; lean_object* x_7; 
-lean_dec(x_1);
-x_6 = lean_box(0);
-x_7 = lean_alloc_ctor(0, 2, 0);
-lean_ctor_set(x_7, 0, x_6);
-lean_ctor_set(x_7, 1, x_2);
-return x_7;
-}
-}
-}
-LEAN_EXPORT lean_object* l_List_elem___at_Lean_Expr_FindImpl_checkVisited___spec__2___boxed(lean_object* x_1, lean_object* x_2) {
-_start:
-{
-uint8_t x_3; lean_object* x_4; 
-x_3 = l_List_elem___at_Lean_Expr_FindImpl_checkVisited___spec__2(x_1, x_2);
-lean_dec(x_2);
-lean_dec(x_1);
-x_4 = lean_box(x_3);
-return x_4;
-}
-}
-LEAN_EXPORT lean_object* l_List_replace___at_Lean_Expr_FindImpl_checkVisited___spec__7___boxed(lean_object* x_1, lean_object* x_2, lean_object* x_3) {
-_start:
-{
-lean_object* x_4; 
-x_4 = l_List_replace___at_Lean_Expr_FindImpl_checkVisited___spec__7(x_1, x_2, x_3);
-lean_dec(x_2);
-return x_4;
-}
-}
-LEAN_EXPORT lean_object* l_Lean_HashSetImp_contains___at_Lean_Expr_FindImpl_checkVisited___spec__8___boxed(lean_object* x_1, lean_object* x_2) {
-_start:
-{
-uint8_t x_3; lean_object* x_4; 
-x_3 = l_Lean_HashSetImp_contains___at_Lean_Expr_FindImpl_checkVisited___spec__8(x_1, x_2);
-lean_dec(x_2);
-lean_dec(x_1);
-x_4 = lean_box(x_3);
-return x_4;
-}
-}
-LEAN_EXPORT lean_object* l_Lean_Expr_FindImpl_checkVisited___lambda__1___boxed(lean_object* x_1, lean_object* x_2, lean_object* x_3) {
-_start:
-{
-lean_object* x_4; 
-x_4 = l_Lean_Expr_FindImpl_checkVisited___lambda__1(x_1, x_2, x_3);
-lean_dec(x_2);
-return x_4;
-}
-}
-LEAN_EXPORT lean_object* l_Lean_Expr_FindImpl_findM_x3f_visit(lean_object* x_1, lean_object* x_2, lean_object* x_3) {
-_start:
-{
-lean_object* x_4; lean_object* x_5; uint8_t x_166; 
-x_166 = l_Lean_HashSetImp_contains___at_Lean_Expr_FindImpl_checkVisited___spec__8(x_3, x_2);
-if (x_166 == 0)
-{
-lean_object* x_167; lean_object* x_168; lean_object* x_169; lean_object* x_170; 
-x_167 = lean_box(0);
-lean_inc(x_2);
-x_168 = l_Lean_Expr_FindImpl_checkVisited___lambda__1(x_2, x_167, x_3);
-x_169 = lean_ctor_get(x_168, 0);
-lean_inc(x_169);
-x_170 = lean_ctor_get(x_168, 1);
-lean_inc(x_170);
-lean_dec(x_168);
-x_4 = x_169;
-x_5 = x_170;
-goto block_165;
-}
-else
-{
-lean_object* x_171; 
-x_171 = lean_box(0);
-x_4 = x_171;
-x_5 = x_3;
-goto block_165;
-}
-block_165:
-{
-if (lean_obj_tag(x_4) == 0)
-{
-lean_object* x_6; lean_object* x_7; 
-lean_dec(x_2);
-lean_dec(x_1);
-x_6 = lean_box(0);
-x_7 = lean_alloc_ctor(0, 2, 0);
-lean_ctor_set(x_7, 0, x_6);
-lean_ctor_set(x_7, 1, x_5);
-return x_7;
-}
-else
-{
-uint8_t x_8; 
-x_8 = !lean_is_exclusive(x_4);
-if (x_8 == 0)
-{
-lean_object* x_9; lean_object* x_10; uint8_t x_11; 
-x_9 = lean_ctor_get(x_4, 0);
-lean_dec(x_9);
-lean_inc(x_1);
-lean_inc(x_2);
-x_10 = lean_apply_1(x_1, x_2);
-x_11 = lean_unbox(x_10);
-lean_dec(x_10);
-if (x_11 == 0)
-{
-lean_free_object(x_4);
-switch (lean_obj_tag(x_2)) {
-case 5:
-{
-lean_object* x_12; lean_object* x_13; lean_object* x_14; lean_object* x_15; 
-x_12 = lean_ctor_get(x_2, 0);
-lean_inc(x_12);
-x_13 = lean_ctor_get(x_2, 1);
-lean_inc(x_13);
-lean_dec(x_2);
-lean_inc(x_1);
-x_14 = l_Lean_Expr_FindImpl_findM_x3f_visit(x_1, x_12, x_5);
-x_15 = lean_ctor_get(x_14, 0);
-lean_inc(x_15);
-if (lean_obj_tag(x_15) == 0)
-{
-lean_object* x_16; 
-x_16 = lean_ctor_get(x_14, 1);
-lean_inc(x_16);
-lean_dec(x_14);
-x_2 = x_13;
-x_3 = x_16;
-goto _start;
-}
-else
-{
-uint8_t x_18; 
-lean_dec(x_13);
-lean_dec(x_1);
-x_18 = !lean_is_exclusive(x_14);
-if (x_18 == 0)
-{
-lean_object* x_19; uint8_t x_20; 
-x_19 = lean_ctor_get(x_14, 0);
-lean_dec(x_19);
-x_20 = !lean_is_exclusive(x_15);
-if (x_20 == 0)
-{
-return x_14;
-}
-else
-{
-lean_object* x_21; lean_object* x_22; 
-x_21 = lean_ctor_get(x_15, 0);
-lean_inc(x_21);
-lean_dec(x_15);
-x_22 = lean_alloc_ctor(1, 1, 0);
-lean_ctor_set(x_22, 0, x_21);
-lean_ctor_set(x_14, 0, x_22);
-return x_14;
-}
-}
-else
-{
-lean_object* x_23; lean_object* x_24; lean_object* x_25; lean_object* x_26; lean_object* x_27; 
-x_23 = lean_ctor_get(x_14, 1);
-lean_inc(x_23);
-lean_dec(x_14);
-x_24 = lean_ctor_get(x_15, 0);
-lean_inc(x_24);
-if (lean_is_exclusive(x_15)) {
- lean_ctor_release(x_15, 0);
- x_25 = x_15;
-} else {
- lean_dec_ref(x_15);
- x_25 = lean_box(0);
-}
-if (lean_is_scalar(x_25)) {
- x_26 = lean_alloc_ctor(1, 1, 0);
-} else {
- x_26 = x_25;
-}
-lean_ctor_set(x_26, 0, x_24);
-x_27 = lean_alloc_ctor(0, 2, 0);
-lean_ctor_set(x_27, 0, x_26);
-lean_ctor_set(x_27, 1, x_23);
-return x_27;
-}
-}
-}
-case 6:
-{
-lean_object* x_28; lean_object* x_29; lean_object* x_30; lean_object* x_31; 
-x_28 = lean_ctor_get(x_2, 1);
-lean_inc(x_28);
-x_29 = lean_ctor_get(x_2, 2);
-lean_inc(x_29);
-lean_dec(x_2);
-lean_inc(x_1);
-x_30 = l_Lean_Expr_FindImpl_findM_x3f_visit(x_1, x_28, x_5);
-x_31 = lean_ctor_get(x_30, 0);
-lean_inc(x_31);
-if (lean_obj_tag(x_31) == 0)
-{
-lean_object* x_32; 
-x_32 = lean_ctor_get(x_30, 1);
-lean_inc(x_32);
-lean_dec(x_30);
-x_2 = x_29;
-x_3 = x_32;
-goto _start;
-}
-else
-{
-uint8_t x_34; 
-lean_dec(x_29);
-lean_dec(x_1);
-x_34 = !lean_is_exclusive(x_30);
-if (x_34 == 0)
-{
-lean_object* x_35; uint8_t x_36; 
-x_35 = lean_ctor_get(x_30, 0);
-lean_dec(x_35);
-x_36 = !lean_is_exclusive(x_31);
-if (x_36 == 0)
-{
-return x_30;
-}
-else
-{
-lean_object* x_37; lean_object* x_38; 
-x_37 = lean_ctor_get(x_31, 0);
-lean_inc(x_37);
-lean_dec(x_31);
-x_38 = lean_alloc_ctor(1, 1, 0);
-lean_ctor_set(x_38, 0, x_37);
-lean_ctor_set(x_30, 0, x_38);
-return x_30;
-}
-}
-else
-{
-lean_object* x_39; lean_object* x_40; lean_object* x_41; lean_object* x_42; lean_object* x_43; 
-x_39 = lean_ctor_get(x_30, 1);
-lean_inc(x_39);
-lean_dec(x_30);
-x_40 = lean_ctor_get(x_31, 0);
-lean_inc(x_40);
-if (lean_is_exclusive(x_31)) {
- lean_ctor_release(x_31, 0);
- x_41 = x_31;
-} else {
- lean_dec_ref(x_31);
- x_41 = lean_box(0);
-}
-if (lean_is_scalar(x_41)) {
- x_42 = lean_alloc_ctor(1, 1, 0);
-} else {
- x_42 = x_41;
-}
-lean_ctor_set(x_42, 0, x_40);
-x_43 = lean_alloc_ctor(0, 2, 0);
-lean_ctor_set(x_43, 0, x_42);
-lean_ctor_set(x_43, 1, x_39);
-return x_43;
-}
-}
-}
-case 7:
-{
-lean_object* x_44; lean_object* x_45; lean_object* x_46; lean_object* x_47; 
-x_44 = lean_ctor_get(x_2, 1);
-lean_inc(x_44);
-x_45 = lean_ctor_get(x_2, 2);
-lean_inc(x_45);
-lean_dec(x_2);
-lean_inc(x_1);
-x_46 = l_Lean_Expr_FindImpl_findM_x3f_visit(x_1, x_44, x_5);
-x_47 = lean_ctor_get(x_46, 0);
-lean_inc(x_47);
-if (lean_obj_tag(x_47) == 0)
-{
-lean_object* x_48; 
-x_48 = lean_ctor_get(x_46, 1);
-lean_inc(x_48);
-lean_dec(x_46);
-x_2 = x_45;
-x_3 = x_48;
-goto _start;
-}
-else
-{
-uint8_t x_50; 
-lean_dec(x_45);
-lean_dec(x_1);
-x_50 = !lean_is_exclusive(x_46);
-if (x_50 == 0)
-{
-lean_object* x_51; uint8_t x_52; 
-x_51 = lean_ctor_get(x_46, 0);
-lean_dec(x_51);
-x_52 = !lean_is_exclusive(x_47);
-if (x_52 == 0)
-{
-return x_46;
-}
-else
-{
-lean_object* x_53; lean_object* x_54; 
-x_53 = lean_ctor_get(x_47, 0);
-lean_inc(x_53);
-lean_dec(x_47);
-x_54 = lean_alloc_ctor(1, 1, 0);
-lean_ctor_set(x_54, 0, x_53);
-lean_ctor_set(x_46, 0, x_54);
-return x_46;
-}
-}
-else
-{
-lean_object* x_55; lean_object* x_56; lean_object* x_57; lean_object* x_58; lean_object* x_59; 
-x_55 = lean_ctor_get(x_46, 1);
-lean_inc(x_55);
-lean_dec(x_46);
-x_56 = lean_ctor_get(x_47, 0);
-lean_inc(x_56);
-if (lean_is_exclusive(x_47)) {
- lean_ctor_release(x_47, 0);
- x_57 = x_47;
-} else {
- lean_dec_ref(x_47);
- x_57 = lean_box(0);
-}
-if (lean_is_scalar(x_57)) {
- x_58 = lean_alloc_ctor(1, 1, 0);
-} else {
- x_58 = x_57;
-}
-lean_ctor_set(x_58, 0, x_56);
-x_59 = lean_alloc_ctor(0, 2, 0);
-lean_ctor_set(x_59, 0, x_58);
-lean_ctor_set(x_59, 1, x_55);
-return x_59;
-}
-}
-}
-case 8:
-{
-lean_object* x_60; lean_object* x_61; lean_object* x_62; lean_object* x_63; lean_object* x_64; 
-x_60 = lean_ctor_get(x_2, 1);
-lean_inc(x_60);
-x_61 = lean_ctor_get(x_2, 2);
-lean_inc(x_61);
-x_62 = lean_ctor_get(x_2, 3);
-lean_inc(x_62);
-lean_dec(x_2);
-lean_inc(x_1);
-x_63 = l_Lean_Expr_FindImpl_findM_x3f_visit(x_1, x_60, x_5);
-x_64 = lean_ctor_get(x_63, 0);
-lean_inc(x_64);
-if (lean_obj_tag(x_64) == 0)
-{
-lean_object* x_65; lean_object* x_66; lean_object* x_67; 
-x_65 = lean_ctor_get(x_63, 1);
-lean_inc(x_65);
-lean_dec(x_63);
-lean_inc(x_1);
-x_66 = l_Lean_Expr_FindImpl_findM_x3f_visit(x_1, x_61, x_65);
-x_67 = lean_ctor_get(x_66, 0);
-lean_inc(x_67);
-if (lean_obj_tag(x_67) == 0)
-{
-lean_object* x_68; 
-x_68 = lean_ctor_get(x_66, 1);
-lean_inc(x_68);
-lean_dec(x_66);
-x_2 = x_62;
-x_3 = x_68;
-goto _start;
-}
-else
-{
-uint8_t x_70; 
-lean_dec(x_62);
-lean_dec(x_1);
-x_70 = !lean_is_exclusive(x_66);
-if (x_70 == 0)
-{
-lean_object* x_71; uint8_t x_72; 
-x_71 = lean_ctor_get(x_66, 0);
-lean_dec(x_71);
-x_72 = !lean_is_exclusive(x_67);
-if (x_72 == 0)
-{
-return x_66;
-}
-else
-{
-lean_object* x_73; lean_object* x_74; 
-x_73 = lean_ctor_get(x_67, 0);
-lean_inc(x_73);
-lean_dec(x_67);
-x_74 = lean_alloc_ctor(1, 1, 0);
-lean_ctor_set(x_74, 0, x_73);
-lean_ctor_set(x_66, 0, x_74);
-return x_66;
-}
-}
-else
-{
-lean_object* x_75; lean_object* x_76; lean_object* x_77; lean_object* x_78; lean_object* x_79; 
-x_75 = lean_ctor_get(x_66, 1);
-lean_inc(x_75);
-lean_dec(x_66);
-x_76 = lean_ctor_get(x_67, 0);
-lean_inc(x_76);
-if (lean_is_exclusive(x_67)) {
- lean_ctor_release(x_67, 0);
- x_77 = x_67;
-} else {
- lean_dec_ref(x_67);
- x_77 = lean_box(0);
-}
-if (lean_is_scalar(x_77)) {
- x_78 = lean_alloc_ctor(1, 1, 0);
-} else {
- x_78 = x_77;
-}
-lean_ctor_set(x_78, 0, x_76);
-x_79 = lean_alloc_ctor(0, 2, 0);
-lean_ctor_set(x_79, 0, x_78);
-lean_ctor_set(x_79, 1, x_75);
-return x_79;
-}
-}
-}
-else
-{
-uint8_t x_80; 
-lean_dec(x_62);
-lean_dec(x_61);
-lean_dec(x_1);
-x_80 = !lean_is_exclusive(x_63);
-if (x_80 == 0)
-{
-lean_object* x_81; uint8_t x_82; 
-x_81 = lean_ctor_get(x_63, 0);
-lean_dec(x_81);
-x_82 = !lean_is_exclusive(x_64);
-if (x_82 == 0)
-{
-return x_63;
-}
-else
-{
-lean_object* x_83; lean_object* x_84; 
-x_83 = lean_ctor_get(x_64, 0);
-lean_inc(x_83);
-lean_dec(x_64);
-x_84 = lean_alloc_ctor(1, 1, 0);
-lean_ctor_set(x_84, 0, x_83);
-lean_ctor_set(x_63, 0, x_84);
-return x_63;
-}
-}
-else
-{
-lean_object* x_85; lean_object* x_86; lean_object* x_87; lean_object* x_88; lean_object* x_89; 
-x_85 = lean_ctor_get(x_63, 1);
-lean_inc(x_85);
-lean_dec(x_63);
-x_86 = lean_ctor_get(x_64, 0);
-lean_inc(x_86);
-if (lean_is_exclusive(x_64)) {
- lean_ctor_release(x_64, 0);
- x_87 = x_64;
-} else {
- lean_dec_ref(x_64);
- x_87 = lean_box(0);
-}
-if (lean_is_scalar(x_87)) {
- x_88 = lean_alloc_ctor(1, 1, 0);
-} else {
- x_88 = x_87;
-}
-lean_ctor_set(x_88, 0, x_86);
-x_89 = lean_alloc_ctor(0, 2, 0);
-lean_ctor_set(x_89, 0, x_88);
-lean_ctor_set(x_89, 1, x_85);
-return x_89;
-}
-}
-}
-case 10:
-{
-lean_object* x_90; 
-x_90 = lean_ctor_get(x_2, 1);
-lean_inc(x_90);
-lean_dec(x_2);
-x_2 = x_90;
-x_3 = x_5;
-goto _start;
-}
-case 11:
-{
-lean_object* x_92; 
-x_92 = lean_ctor_get(x_2, 2);
-lean_inc(x_92);
-lean_dec(x_2);
-x_2 = x_92;
-x_3 = x_5;
-goto _start;
-}
-default: 
-{
-lean_object* x_94; lean_object* x_95; 
-lean_dec(x_2);
-lean_dec(x_1);
-x_94 = lean_box(0);
-x_95 = lean_alloc_ctor(0, 2, 0);
-lean_ctor_set(x_95, 0, x_94);
-lean_ctor_set(x_95, 1, x_5);
-return x_95;
-}
-}
-}
-else
-{
-lean_object* x_96; 
-lean_dec(x_1);
-lean_ctor_set(x_4, 0, x_2);
-x_96 = lean_alloc_ctor(0, 2, 0);
-lean_ctor_set(x_96, 0, x_4);
-lean_ctor_set(x_96, 1, x_5);
-return x_96;
-}
-}
-else
-{
-lean_object* x_97; uint8_t x_98; 
-lean_dec(x_4);
-lean_inc(x_1);
-lean_inc(x_2);
-x_97 = lean_apply_1(x_1, x_2);
-x_98 = lean_unbox(x_97);
-lean_dec(x_97);
-if (x_98 == 0)
-{
-switch (lean_obj_tag(x_2)) {
-case 5:
-{
-lean_object* x_99; lean_object* x_100; lean_object* x_101; lean_object* x_102; 
-x_99 = lean_ctor_get(x_2, 0);
-lean_inc(x_99);
-x_100 = lean_ctor_get(x_2, 1);
-lean_inc(x_100);
-lean_dec(x_2);
-lean_inc(x_1);
-x_101 = l_Lean_Expr_FindImpl_findM_x3f_visit(x_1, x_99, x_5);
-x_102 = lean_ctor_get(x_101, 0);
-lean_inc(x_102);
-if (lean_obj_tag(x_102) == 0)
-{
-lean_object* x_103; 
-x_103 = lean_ctor_get(x_101, 1);
-lean_inc(x_103);
-lean_dec(x_101);
-x_2 = x_100;
-x_3 = x_103;
-goto _start;
-}
-else
-{
-lean_object* x_105; lean_object* x_106; lean_object* x_107; lean_object* x_108; lean_object* x_109; lean_object* x_110; 
-lean_dec(x_100);
-lean_dec(x_1);
-x_105 = lean_ctor_get(x_101, 1);
-lean_inc(x_105);
-if (lean_is_exclusive(x_101)) {
- lean_ctor_release(x_101, 0);
- lean_ctor_release(x_101, 1);
- x_106 = x_101;
-} else {
- lean_dec_ref(x_101);
- x_106 = lean_box(0);
-}
-x_107 = lean_ctor_get(x_102, 0);
-lean_inc(x_107);
-if (lean_is_exclusive(x_102)) {
- lean_ctor_release(x_102, 0);
- x_108 = x_102;
-} else {
- lean_dec_ref(x_102);
- x_108 = lean_box(0);
-}
-if (lean_is_scalar(x_108)) {
- x_109 = lean_alloc_ctor(1, 1, 0);
-} else {
- x_109 = x_108;
-}
-lean_ctor_set(x_109, 0, x_107);
-if (lean_is_scalar(x_106)) {
- x_110 = lean_alloc_ctor(0, 2, 0);
-} else {
- x_110 = x_106;
-}
-lean_ctor_set(x_110, 0, x_109);
-lean_ctor_set(x_110, 1, x_105);
-return x_110;
-}
-}
-case 6:
-{
-lean_object* x_111; lean_object* x_112; lean_object* x_113; lean_object* x_114; 
-x_111 = lean_ctor_get(x_2, 1);
-lean_inc(x_111);
-x_112 = lean_ctor_get(x_2, 2);
-lean_inc(x_112);
-lean_dec(x_2);
-lean_inc(x_1);
-x_113 = l_Lean_Expr_FindImpl_findM_x3f_visit(x_1, x_111, x_5);
-x_114 = lean_ctor_get(x_113, 0);
-lean_inc(x_114);
-if (lean_obj_tag(x_114) == 0)
-{
-lean_object* x_115; 
-x_115 = lean_ctor_get(x_113, 1);
-lean_inc(x_115);
-lean_dec(x_113);
-x_2 = x_112;
-x_3 = x_115;
-goto _start;
-}
-else
-{
-lean_object* x_117; lean_object* x_118; lean_object* x_119; lean_object* x_120; lean_object* x_121; lean_object* x_122; 
-lean_dec(x_112);
-lean_dec(x_1);
-x_117 = lean_ctor_get(x_113, 1);
-lean_inc(x_117);
-if (lean_is_exclusive(x_113)) {
- lean_ctor_release(x_113, 0);
- lean_ctor_release(x_113, 1);
- x_118 = x_113;
-} else {
- lean_dec_ref(x_113);
- x_118 = lean_box(0);
-}
-x_119 = lean_ctor_get(x_114, 0);
-lean_inc(x_119);
-if (lean_is_exclusive(x_114)) {
- lean_ctor_release(x_114, 0);
- x_120 = x_114;
-} else {
- lean_dec_ref(x_114);
- x_120 = lean_box(0);
-}
-if (lean_is_scalar(x_120)) {
- x_121 = lean_alloc_ctor(1, 1, 0);
-} else {
- x_121 = x_120;
-}
-lean_ctor_set(x_121, 0, x_119);
-if (lean_is_scalar(x_118)) {
- x_122 = lean_alloc_ctor(0, 2, 0);
-} else {
- x_122 = x_118;
-}
-lean_ctor_set(x_122, 0, x_121);
-lean_ctor_set(x_122, 1, x_117);
-return x_122;
-}
-}
-case 7:
-{
-lean_object* x_123; lean_object* x_124; lean_object* x_125; lean_object* x_126; 
-x_123 = lean_ctor_get(x_2, 1);
-lean_inc(x_123);
-x_124 = lean_ctor_get(x_2, 2);
-lean_inc(x_124);
-lean_dec(x_2);
-lean_inc(x_1);
-x_125 = l_Lean_Expr_FindImpl_findM_x3f_visit(x_1, x_123, x_5);
-x_126 = lean_ctor_get(x_125, 0);
-lean_inc(x_126);
-if (lean_obj_tag(x_126) == 0)
-{
-lean_object* x_127; 
-x_127 = lean_ctor_get(x_125, 1);
-lean_inc(x_127);
-lean_dec(x_125);
-x_2 = x_124;
-x_3 = x_127;
-goto _start;
-}
-else
-{
-lean_object* x_129; lean_object* x_130; lean_object* x_131; lean_object* x_132; lean_object* x_133; lean_object* x_134; 
-lean_dec(x_124);
-lean_dec(x_1);
-x_129 = lean_ctor_get(x_125, 1);
-lean_inc(x_129);
-if (lean_is_exclusive(x_125)) {
- lean_ctor_release(x_125, 0);
- lean_ctor_release(x_125, 1);
- x_130 = x_125;
-} else {
- lean_dec_ref(x_125);
- x_130 = lean_box(0);
-}
-x_131 = lean_ctor_get(x_126, 0);
-lean_inc(x_131);
-if (lean_is_exclusive(x_126)) {
- lean_ctor_release(x_126, 0);
- x_132 = x_126;
-} else {
- lean_dec_ref(x_126);
- x_132 = lean_box(0);
-}
-if (lean_is_scalar(x_132)) {
- x_133 = lean_alloc_ctor(1, 1, 0);
-} else {
- x_133 = x_132;
-}
-lean_ctor_set(x_133, 0, x_131);
-if (lean_is_scalar(x_130)) {
- x_134 = lean_alloc_ctor(0, 2, 0);
-} else {
- x_134 = x_130;
-}
-lean_ctor_set(x_134, 0, x_133);
-lean_ctor_set(x_134, 1, x_129);
-return x_134;
-}
-}
-case 8:
-{
-lean_object* x_135; lean_object* x_136; lean_object* x_137; lean_object* x_138; lean_object* x_139; 
-x_135 = lean_ctor_get(x_2, 1);
-lean_inc(x_135);
-x_136 = lean_ctor_get(x_2, 2);
-lean_inc(x_136);
-x_137 = lean_ctor_get(x_2, 3);
-lean_inc(x_137);
-lean_dec(x_2);
-lean_inc(x_1);
-x_138 = l_Lean_Expr_FindImpl_findM_x3f_visit(x_1, x_135, x_5);
-x_139 = lean_ctor_get(x_138, 0);
-lean_inc(x_139);
-if (lean_obj_tag(x_139) == 0)
-{
-lean_object* x_140; lean_object* x_141; lean_object* x_142; 
-x_140 = lean_ctor_get(x_138, 1);
-lean_inc(x_140);
-lean_dec(x_138);
-lean_inc(x_1);
-x_141 = l_Lean_Expr_FindImpl_findM_x3f_visit(x_1, x_136, x_140);
-x_142 = lean_ctor_get(x_141, 0);
-lean_inc(x_142);
-if (lean_obj_tag(x_142) == 0)
-{
-lean_object* x_143; 
-x_143 = lean_ctor_get(x_141, 1);
-lean_inc(x_143);
-lean_dec(x_141);
-x_2 = x_137;
-x_3 = x_143;
-goto _start;
-}
-else
-{
-lean_object* x_145; lean_object* x_146; lean_object* x_147; lean_object* x_148; lean_object* x_149; lean_object* x_150; 
-lean_dec(x_137);
-lean_dec(x_1);
-x_145 = lean_ctor_get(x_141, 1);
-lean_inc(x_145);
-if (lean_is_exclusive(x_141)) {
- lean_ctor_release(x_141, 0);
- lean_ctor_release(x_141, 1);
- x_146 = x_141;
-} else {
- lean_dec_ref(x_141);
- x_146 = lean_box(0);
-}
-x_147 = lean_ctor_get(x_142, 0);
-lean_inc(x_147);
-if (lean_is_exclusive(x_142)) {
- lean_ctor_release(x_142, 0);
- x_148 = x_142;
-} else {
- lean_dec_ref(x_142);
- x_148 = lean_box(0);
-}
-if (lean_is_scalar(x_148)) {
- x_149 = lean_alloc_ctor(1, 1, 0);
-} else {
- x_149 = x_148;
-}
-lean_ctor_set(x_149, 0, x_147);
-if (lean_is_scalar(x_146)) {
- x_150 = lean_alloc_ctor(0, 2, 0);
-} else {
- x_150 = x_146;
-}
-lean_ctor_set(x_150, 0, x_149);
-lean_ctor_set(x_150, 1, x_145);
-return x_150;
-}
-}
-else
-{
-lean_object* x_151; lean_object* x_152; lean_object* x_153; lean_object* x_154; lean_object* x_155; lean_object* x_156; 
-lean_dec(x_137);
-lean_dec(x_136);
-lean_dec(x_1);
-x_151 = lean_ctor_get(x_138, 1);
-lean_inc(x_151);
-if (lean_is_exclusive(x_138)) {
- lean_ctor_release(x_138, 0);
- lean_ctor_release(x_138, 1);
- x_152 = x_138;
-} else {
- lean_dec_ref(x_138);
- x_152 = lean_box(0);
-}
-x_153 = lean_ctor_get(x_139, 0);
-lean_inc(x_153);
-if (lean_is_exclusive(x_139)) {
- lean_ctor_release(x_139, 0);
- x_154 = x_139;
-} else {
- lean_dec_ref(x_139);
- x_154 = lean_box(0);
-}
-if (lean_is_scalar(x_154)) {
- x_155 = lean_alloc_ctor(1, 1, 0);
-} else {
- x_155 = x_154;
-}
-lean_ctor_set(x_155, 0, x_153);
-if (lean_is_scalar(x_152)) {
- x_156 = lean_alloc_ctor(0, 2, 0);
-} else {
- x_156 = x_152;
-}
-lean_ctor_set(x_156, 0, x_155);
-lean_ctor_set(x_156, 1, x_151);
-return x_156;
-}
-}
-case 10:
-{
-lean_object* x_157; 
-x_157 = lean_ctor_get(x_2, 1);
-lean_inc(x_157);
-lean_dec(x_2);
-x_2 = x_157;
-x_3 = x_5;
-goto _start;
-}
-case 11:
-{
-lean_object* x_159; 
-x_159 = lean_ctor_get(x_2, 2);
-lean_inc(x_159);
-lean_dec(x_2);
-x_2 = x_159;
-x_3 = x_5;
-goto _start;
-}
-default: 
-{
-lean_object* x_161; lean_object* x_162; 
-lean_dec(x_2);
-lean_dec(x_1);
-x_161 = lean_box(0);
-x_162 = lean_alloc_ctor(0, 2, 0);
-lean_ctor_set(x_162, 0, x_161);
-lean_ctor_set(x_162, 1, x_5);
-return x_162;
-}
-}
-}
-else
-{
-lean_object* x_163; lean_object* x_164; 
-lean_dec(x_1);
-x_163 = lean_alloc_ctor(1, 1, 0);
-lean_ctor_set(x_163, 0, x_2);
-x_164 = lean_alloc_ctor(0, 2, 0);
-lean_ctor_set(x_164, 0, x_163);
-lean_ctor_set(x_164, 1, x_5);
-return x_164;
-}
-}
-}
-}
-}
-}
-LEAN_EXPORT lean_object* l_Lean_Expr_FindImpl_findM_x3f(lean_object* x_1, lean_object* x_2, lean_object* x_3) {
-_start:
-{
-lean_object* x_4; 
-x_4 = l_Lean_Expr_FindImpl_findM_x3f_visit(x_1, x_2, x_3);
-return x_4;
-}
-}
-static lean_object* _init_l_Lean_Expr_FindImpl_findUnsafe_x3f___closed__1() {
-_start:
-{
-lean_object* x_1; lean_object* x_2; 
-x_1 = lean_unsigned_to_nat(64u);
-x_2 = l_Lean_mkHashSetImp___rarg(x_1);
-return x_2;
-}
-}
-LEAN_EXPORT lean_object* l_Lean_Expr_FindImpl_findUnsafe_x3f(lean_object* x_1, lean_object* x_2) {
-_start:
-{
-lean_object* x_3; lean_object* x_4; lean_object* x_5; 
-x_3 = l_Lean_Expr_FindImpl_findUnsafe_x3f___closed__1;
-x_4 = l_Lean_Expr_FindImpl_findM_x3f_visit(x_1, x_2, x_3);
-x_5 = lean_ctor_get(x_4, 0);
-lean_inc(x_5);
-lean_dec(x_4);
-return x_5;
-}
-}
 LEAN_EXPORT lean_object* l_Lean_Expr_findImpl_x3f___boxed(lean_object* x_1, lean_object* x_2) {
 _start:
 {
@@ -1439,6 +44,24 @@ lean_dec(x_1);
 return x_3;
 }
 }
+LEAN_EXPORT lean_object* l_Lean_Expr_find_x3f(lean_object* x_1, lean_object* x_2) {
+_start:
+{
+lean_object* x_3; 
+x_3 = lean_find_expr(x_1, x_2);
+return x_3;
+}
+}
+LEAN_EXPORT lean_object* l_Lean_Expr_find_x3f___boxed(lean_object* x_1, lean_object* x_2) {
+_start:
+{
+lean_object* x_3; 
+x_3 = l_Lean_Expr_find_x3f(x_1, x_2);
+lean_dec(x_2);
+lean_dec(x_1);
+return x_3;
+}
+}
 LEAN_EXPORT uint8_t l_Lean_Expr_occurs___lambda__1(lean_object* x_1, lean_object* x_2) {
 _start:
 {
@@ -1453,7 +76,8 @@ _start:
 lean_object* x_3; lean_object* x_4; 
 x_3 = lean_alloc_closure((void*)(l_Lean_Expr_occurs___lambda__1___boxed), 2, 1);
 lean_closure_set(x_3, 0, x_1);
-x_4 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_3, x_2);
+x_4 = lean_find_expr(x_3, x_2);
+lean_dec(x_3);
 if (lean_obj_tag(x_4) == 0)
 {
 uint8_t x_5; 
@@ -1485,6 +109,7 @@ _start:
 {
 uint8_t x_3; lean_object* x_4; 
 x_3 = l_Lean_Expr_occurs(x_1, x_2);
+lean_dec(x_2);
 x_4 = lean_box(x_3);
 return x_4;
 }
@@ -1586,857 +211,22 @@ lean_dec(x_1);
 return x_3;
 }
 }
-LEAN_EXPORT lean_object* l_Lean_Expr_FindExtImpl_findM_x3f_visitApp(lean_object* x_1, lean_object* x_2, lean_object* x_3) {
+LEAN_EXPORT lean_object* l_Lean_Expr_findExt_x3f(lean_object* x_1, lean_object* x_2) {
 _start:
 {
-if (lean_obj_tag(x_2) == 5)
-{
-lean_object* x_4; lean_object* x_5; lean_object* x_6; lean_object* x_7; 
-x_4 = lean_ctor_get(x_2, 0);
-lean_inc(x_4);
-x_5 = lean_ctor_get(x_2, 1);
-lean_inc(x_5);
-lean_dec(x_2);
-lean_inc(x_1);
-x_6 = l_Lean_Expr_FindExtImpl_findM_x3f_visitApp(x_1, x_4, x_3);
-x_7 = lean_ctor_get(x_6, 0);
-lean_inc(x_7);
-if (lean_obj_tag(x_7) == 0)
-{
-lean_object* x_8; lean_object* x_9; 
-x_8 = lean_ctor_get(x_6, 1);
-lean_inc(x_8);
-lean_dec(x_6);
-x_9 = l_Lean_Expr_FindExtImpl_findM_x3f_visit(x_1, x_5, x_8);
-return x_9;
-}
-else
-{
-uint8_t x_10; 
-lean_dec(x_5);
-lean_dec(x_1);
-x_10 = !lean_is_exclusive(x_6);
-if (x_10 == 0)
-{
-lean_object* x_11; uint8_t x_12; 
-x_11 = lean_ctor_get(x_6, 0);
-lean_dec(x_11);
-x_12 = !lean_is_exclusive(x_7);
-if (x_12 == 0)
-{
-return x_6;
-}
-else
-{
-lean_object* x_13; lean_object* x_14; 
-x_13 = lean_ctor_get(x_7, 0);
-lean_inc(x_13);
-lean_dec(x_7);
-x_14 = lean_alloc_ctor(1, 1, 0);
-lean_ctor_set(x_14, 0, x_13);
-lean_ctor_set(x_6, 0, x_14);
-return x_6;
+lean_object* x_3; 
+x_3 = lean_find_ext_expr(x_1, x_2);
+return x_3;
 }
 }
-else
-{
-lean_object* x_15; lean_object* x_16; lean_object* x_17; lean_object* x_18; lean_object* x_19; 
-x_15 = lean_ctor_get(x_6, 1);
-lean_inc(x_15);
-lean_dec(x_6);
-x_16 = lean_ctor_get(x_7, 0);
-lean_inc(x_16);
-if (lean_is_exclusive(x_7)) {
- lean_ctor_release(x_7, 0);
- x_17 = x_7;
-} else {
- lean_dec_ref(x_7);
- x_17 = lean_box(0);
-}
-if (lean_is_scalar(x_17)) {
- x_18 = lean_alloc_ctor(1, 1, 0);
-} else {
- x_18 = x_17;
-}
-lean_ctor_set(x_18, 0, x_16);
-x_19 = lean_alloc_ctor(0, 2, 0);
-lean_ctor_set(x_19, 0, x_18);
-lean_ctor_set(x_19, 1, x_15);
-return x_19;
-}
-}
-}
-else
-{
-lean_object* x_20; 
-x_20 = l_Lean_Expr_FindExtImpl_findM_x3f_visit(x_1, x_2, x_3);
-return x_20;
-}
-}
-}
-LEAN_EXPORT lean_object* l_Lean_Expr_FindExtImpl_findM_x3f_visit(lean_object* x_1, lean_object* x_2, lean_object* x_3) {
+LEAN_EXPORT lean_object* l_Lean_Expr_findExt_x3f___boxed(lean_object* x_1, lean_object* x_2) {
 _start:
 {
-lean_object* x_4; lean_object* x_5; uint8_t x_144; 
-x_144 = l_Lean_HashSetImp_contains___at_Lean_Expr_FindImpl_checkVisited___spec__8(x_3, x_2);
-if (x_144 == 0)
-{
-lean_object* x_145; lean_object* x_146; lean_object* x_147; lean_object* x_148; 
-x_145 = lean_box(0);
-lean_inc(x_2);
-x_146 = l_Lean_Expr_FindImpl_checkVisited___lambda__1(x_2, x_145, x_3);
-x_147 = lean_ctor_get(x_146, 0);
-lean_inc(x_147);
-x_148 = lean_ctor_get(x_146, 1);
-lean_inc(x_148);
-lean_dec(x_146);
-x_4 = x_147;
-x_5 = x_148;
-goto block_143;
-}
-else
-{
-lean_object* x_149; 
-x_149 = lean_box(0);
-x_4 = x_149;
-x_5 = x_3;
-goto block_143;
-}
-block_143:
-{
-if (lean_obj_tag(x_4) == 0)
-{
-lean_object* x_6; lean_object* x_7; 
+lean_object* x_3; 
+x_3 = l_Lean_Expr_findExt_x3f(x_1, x_2);
 lean_dec(x_2);
 lean_dec(x_1);
-x_6 = lean_box(0);
-x_7 = lean_alloc_ctor(0, 2, 0);
-lean_ctor_set(x_7, 0, x_6);
-lean_ctor_set(x_7, 1, x_5);
-return x_7;
-}
-else
-{
-uint8_t x_8; 
-x_8 = !lean_is_exclusive(x_4);
-if (x_8 == 0)
-{
-lean_object* x_9; lean_object* x_10; uint8_t x_11; 
-x_9 = lean_ctor_get(x_4, 0);
-lean_dec(x_9);
-lean_inc(x_1);
-lean_inc(x_2);
-x_10 = lean_apply_1(x_1, x_2);
-x_11 = lean_unbox(x_10);
-lean_dec(x_10);
-switch (x_11) {
-case 0:
-{
-lean_object* x_12; 
-lean_dec(x_1);
-lean_ctor_set(x_4, 0, x_2);
-x_12 = lean_alloc_ctor(0, 2, 0);
-lean_ctor_set(x_12, 0, x_4);
-lean_ctor_set(x_12, 1, x_5);
-return x_12;
-}
-case 1:
-{
-lean_free_object(x_4);
-switch (lean_obj_tag(x_2)) {
-case 5:
-{
-lean_object* x_13; 
-x_13 = l_Lean_Expr_FindExtImpl_findM_x3f_visitApp(x_1, x_2, x_5);
-return x_13;
-}
-case 6:
-{
-lean_object* x_14; lean_object* x_15; lean_object* x_16; lean_object* x_17; 
-x_14 = lean_ctor_get(x_2, 1);
-lean_inc(x_14);
-x_15 = lean_ctor_get(x_2, 2);
-lean_inc(x_15);
-lean_dec(x_2);
-lean_inc(x_1);
-x_16 = l_Lean_Expr_FindExtImpl_findM_x3f_visit(x_1, x_14, x_5);
-x_17 = lean_ctor_get(x_16, 0);
-lean_inc(x_17);
-if (lean_obj_tag(x_17) == 0)
-{
-lean_object* x_18; 
-x_18 = lean_ctor_get(x_16, 1);
-lean_inc(x_18);
-lean_dec(x_16);
-x_2 = x_15;
-x_3 = x_18;
-goto _start;
-}
-else
-{
-uint8_t x_20; 
-lean_dec(x_15);
-lean_dec(x_1);
-x_20 = !lean_is_exclusive(x_16);
-if (x_20 == 0)
-{
-lean_object* x_21; uint8_t x_22; 
-x_21 = lean_ctor_get(x_16, 0);
-lean_dec(x_21);
-x_22 = !lean_is_exclusive(x_17);
-if (x_22 == 0)
-{
-return x_16;
-}
-else
-{
-lean_object* x_23; lean_object* x_24; 
-x_23 = lean_ctor_get(x_17, 0);
-lean_inc(x_23);
-lean_dec(x_17);
-x_24 = lean_alloc_ctor(1, 1, 0);
-lean_ctor_set(x_24, 0, x_23);
-lean_ctor_set(x_16, 0, x_24);
-return x_16;
-}
-}
-else
-{
-lean_object* x_25; lean_object* x_26; lean_object* x_27; lean_object* x_28; lean_object* x_29; 
-x_25 = lean_ctor_get(x_16, 1);
-lean_inc(x_25);
-lean_dec(x_16);
-x_26 = lean_ctor_get(x_17, 0);
-lean_inc(x_26);
-if (lean_is_exclusive(x_17)) {
- lean_ctor_release(x_17, 0);
- x_27 = x_17;
-} else {
- lean_dec_ref(x_17);
- x_27 = lean_box(0);
-}
-if (lean_is_scalar(x_27)) {
- x_28 = lean_alloc_ctor(1, 1, 0);
-} else {
- x_28 = x_27;
-}
-lean_ctor_set(x_28, 0, x_26);
-x_29 = lean_alloc_ctor(0, 2, 0);
-lean_ctor_set(x_29, 0, x_28);
-lean_ctor_set(x_29, 1, x_25);
-return x_29;
-}
-}
-}
-case 7:
-{
-lean_object* x_30; lean_object* x_31; lean_object* x_32; lean_object* x_33; 
-x_30 = lean_ctor_get(x_2, 1);
-lean_inc(x_30);
-x_31 = lean_ctor_get(x_2, 2);
-lean_inc(x_31);
-lean_dec(x_2);
-lean_inc(x_1);
-x_32 = l_Lean_Expr_FindExtImpl_findM_x3f_visit(x_1, x_30, x_5);
-x_33 = lean_ctor_get(x_32, 0);
-lean_inc(x_33);
-if (lean_obj_tag(x_33) == 0)
-{
-lean_object* x_34; 
-x_34 = lean_ctor_get(x_32, 1);
-lean_inc(x_34);
-lean_dec(x_32);
-x_2 = x_31;
-x_3 = x_34;
-goto _start;
-}
-else
-{
-uint8_t x_36; 
-lean_dec(x_31);
-lean_dec(x_1);
-x_36 = !lean_is_exclusive(x_32);
-if (x_36 == 0)
-{
-lean_object* x_37; uint8_t x_38; 
-x_37 = lean_ctor_get(x_32, 0);
-lean_dec(x_37);
-x_38 = !lean_is_exclusive(x_33);
-if (x_38 == 0)
-{
-return x_32;
-}
-else
-{
-lean_object* x_39; lean_object* x_40; 
-x_39 = lean_ctor_get(x_33, 0);
-lean_inc(x_39);
-lean_dec(x_33);
-x_40 = lean_alloc_ctor(1, 1, 0);
-lean_ctor_set(x_40, 0, x_39);
-lean_ctor_set(x_32, 0, x_40);
-return x_32;
-}
-}
-else
-{
-lean_object* x_41; lean_object* x_42; lean_object* x_43; lean_object* x_44; lean_object* x_45; 
-x_41 = lean_ctor_get(x_32, 1);
-lean_inc(x_41);
-lean_dec(x_32);
-x_42 = lean_ctor_get(x_33, 0);
-lean_inc(x_42);
-if (lean_is_exclusive(x_33)) {
- lean_ctor_release(x_33, 0);
- x_43 = x_33;
-} else {
- lean_dec_ref(x_33);
- x_43 = lean_box(0);
-}
-if (lean_is_scalar(x_43)) {
- x_44 = lean_alloc_ctor(1, 1, 0);
-} else {
- x_44 = x_43;
-}
-lean_ctor_set(x_44, 0, x_42);
-x_45 = lean_alloc_ctor(0, 2, 0);
-lean_ctor_set(x_45, 0, x_44);
-lean_ctor_set(x_45, 1, x_41);
-return x_45;
-}
-}
-}
-case 8:
-{
-lean_object* x_46; lean_object* x_47; lean_object* x_48; lean_object* x_49; lean_object* x_50; 
-x_46 = lean_ctor_get(x_2, 1);
-lean_inc(x_46);
-x_47 = lean_ctor_get(x_2, 2);
-lean_inc(x_47);
-x_48 = lean_ctor_get(x_2, 3);
-lean_inc(x_48);
-lean_dec(x_2);
-lean_inc(x_1);
-x_49 = l_Lean_Expr_FindExtImpl_findM_x3f_visit(x_1, x_46, x_5);
-x_50 = lean_ctor_get(x_49, 0);
-lean_inc(x_50);
-if (lean_obj_tag(x_50) == 0)
-{
-lean_object* x_51; lean_object* x_52; lean_object* x_53; 
-x_51 = lean_ctor_get(x_49, 1);
-lean_inc(x_51);
-lean_dec(x_49);
-lean_inc(x_1);
-x_52 = l_Lean_Expr_FindExtImpl_findM_x3f_visit(x_1, x_47, x_51);
-x_53 = lean_ctor_get(x_52, 0);
-lean_inc(x_53);
-if (lean_obj_tag(x_53) == 0)
-{
-lean_object* x_54; 
-x_54 = lean_ctor_get(x_52, 1);
-lean_inc(x_54);
-lean_dec(x_52);
-x_2 = x_48;
-x_3 = x_54;
-goto _start;
-}
-else
-{
-uint8_t x_56; 
-lean_dec(x_48);
-lean_dec(x_1);
-x_56 = !lean_is_exclusive(x_52);
-if (x_56 == 0)
-{
-lean_object* x_57; uint8_t x_58; 
-x_57 = lean_ctor_get(x_52, 0);
-lean_dec(x_57);
-x_58 = !lean_is_exclusive(x_53);
-if (x_58 == 0)
-{
-return x_52;
-}
-else
-{
-lean_object* x_59; lean_object* x_60; 
-x_59 = lean_ctor_get(x_53, 0);
-lean_inc(x_59);
-lean_dec(x_53);
-x_60 = lean_alloc_ctor(1, 1, 0);
-lean_ctor_set(x_60, 0, x_59);
-lean_ctor_set(x_52, 0, x_60);
-return x_52;
-}
-}
-else
-{
-lean_object* x_61; lean_object* x_62; lean_object* x_63; lean_object* x_64; lean_object* x_65; 
-x_61 = lean_ctor_get(x_52, 1);
-lean_inc(x_61);
-lean_dec(x_52);
-x_62 = lean_ctor_get(x_53, 0);
-lean_inc(x_62);
-if (lean_is_exclusive(x_53)) {
- lean_ctor_release(x_53, 0);
- x_63 = x_53;
-} else {
- lean_dec_ref(x_53);
- x_63 = lean_box(0);
-}
-if (lean_is_scalar(x_63)) {
- x_64 = lean_alloc_ctor(1, 1, 0);
-} else {
- x_64 = x_63;
-}
-lean_ctor_set(x_64, 0, x_62);
-x_65 = lean_alloc_ctor(0, 2, 0);
-lean_ctor_set(x_65, 0, x_64);
-lean_ctor_set(x_65, 1, x_61);
-return x_65;
-}
-}
-}
-else
-{
-uint8_t x_66; 
-lean_dec(x_48);
-lean_dec(x_47);
-lean_dec(x_1);
-x_66 = !lean_is_exclusive(x_49);
-if (x_66 == 0)
-{
-lean_object* x_67; uint8_t x_68; 
-x_67 = lean_ctor_get(x_49, 0);
-lean_dec(x_67);
-x_68 = !lean_is_exclusive(x_50);
-if (x_68 == 0)
-{
-return x_49;
-}
-else
-{
-lean_object* x_69; lean_object* x_70; 
-x_69 = lean_ctor_get(x_50, 0);
-lean_inc(x_69);
-lean_dec(x_50);
-x_70 = lean_alloc_ctor(1, 1, 0);
-lean_ctor_set(x_70, 0, x_69);
-lean_ctor_set(x_49, 0, x_70);
-return x_49;
-}
-}
-else
-{
-lean_object* x_71; lean_object* x_72; lean_object* x_73; lean_object* x_74; lean_object* x_75; 
-x_71 = lean_ctor_get(x_49, 1);
-lean_inc(x_71);
-lean_dec(x_49);
-x_72 = lean_ctor_get(x_50, 0);
-lean_inc(x_72);
-if (lean_is_exclusive(x_50)) {
- lean_ctor_release(x_50, 0);
- x_73 = x_50;
-} else {
- lean_dec_ref(x_50);
- x_73 = lean_box(0);
-}
-if (lean_is_scalar(x_73)) {
- x_74 = lean_alloc_ctor(1, 1, 0);
-} else {
- x_74 = x_73;
-}
-lean_ctor_set(x_74, 0, x_72);
-x_75 = lean_alloc_ctor(0, 2, 0);
-lean_ctor_set(x_75, 0, x_74);
-lean_ctor_set(x_75, 1, x_71);
-return x_75;
-}
-}
-}
-case 10:
-{
-lean_object* x_76; 
-x_76 = lean_ctor_get(x_2, 1);
-lean_inc(x_76);
-lean_dec(x_2);
-x_2 = x_76;
-x_3 = x_5;
-goto _start;
-}
-case 11:
-{
-lean_object* x_78; 
-x_78 = lean_ctor_get(x_2, 2);
-lean_inc(x_78);
-lean_dec(x_2);
-x_2 = x_78;
-x_3 = x_5;
-goto _start;
-}
-default: 
-{
-lean_object* x_80; lean_object* x_81; 
-lean_dec(x_2);
-lean_dec(x_1);
-x_80 = lean_box(0);
-x_81 = lean_alloc_ctor(0, 2, 0);
-lean_ctor_set(x_81, 0, x_80);
-lean_ctor_set(x_81, 1, x_5);
-return x_81;
-}
-}
-}
-default: 
-{
-lean_object* x_82; lean_object* x_83; 
-lean_free_object(x_4);
-lean_dec(x_2);
-lean_dec(x_1);
-x_82 = lean_box(0);
-x_83 = lean_alloc_ctor(0, 2, 0);
-lean_ctor_set(x_83, 0, x_82);
-lean_ctor_set(x_83, 1, x_5);
-return x_83;
-}
-}
-}
-else
-{
-lean_object* x_84; uint8_t x_85; 
-lean_dec(x_4);
-lean_inc(x_1);
-lean_inc(x_2);
-x_84 = lean_apply_1(x_1, x_2);
-x_85 = lean_unbox(x_84);
-lean_dec(x_84);
-switch (x_85) {
-case 0:
-{
-lean_object* x_86; lean_object* x_87; 
-lean_dec(x_1);
-x_86 = lean_alloc_ctor(1, 1, 0);
-lean_ctor_set(x_86, 0, x_2);
-x_87 = lean_alloc_ctor(0, 2, 0);
-lean_ctor_set(x_87, 0, x_86);
-lean_ctor_set(x_87, 1, x_5);
-return x_87;
-}
-case 1:
-{
-switch (lean_obj_tag(x_2)) {
-case 5:
-{
-lean_object* x_88; 
-x_88 = l_Lean_Expr_FindExtImpl_findM_x3f_visitApp(x_1, x_2, x_5);
-return x_88;
-}
-case 6:
-{
-lean_object* x_89; lean_object* x_90; lean_object* x_91; lean_object* x_92; 
-x_89 = lean_ctor_get(x_2, 1);
-lean_inc(x_89);
-x_90 = lean_ctor_get(x_2, 2);
-lean_inc(x_90);
-lean_dec(x_2);
-lean_inc(x_1);
-x_91 = l_Lean_Expr_FindExtImpl_findM_x3f_visit(x_1, x_89, x_5);
-x_92 = lean_ctor_get(x_91, 0);
-lean_inc(x_92);
-if (lean_obj_tag(x_92) == 0)
-{
-lean_object* x_93; 
-x_93 = lean_ctor_get(x_91, 1);
-lean_inc(x_93);
-lean_dec(x_91);
-x_2 = x_90;
-x_3 = x_93;
-goto _start;
-}
-else
-{
-lean_object* x_95; lean_object* x_96; lean_object* x_97; lean_object* x_98; lean_object* x_99; lean_object* x_100; 
-lean_dec(x_90);
-lean_dec(x_1);
-x_95 = lean_ctor_get(x_91, 1);
-lean_inc(x_95);
-if (lean_is_exclusive(x_91)) {
- lean_ctor_release(x_91, 0);
- lean_ctor_release(x_91, 1);
- x_96 = x_91;
-} else {
- lean_dec_ref(x_91);
- x_96 = lean_box(0);
-}
-x_97 = lean_ctor_get(x_92, 0);
-lean_inc(x_97);
-if (lean_is_exclusive(x_92)) {
- lean_ctor_release(x_92, 0);
- x_98 = x_92;
-} else {
- lean_dec_ref(x_92);
- x_98 = lean_box(0);
-}
-if (lean_is_scalar(x_98)) {
- x_99 = lean_alloc_ctor(1, 1, 0);
-} else {
- x_99 = x_98;
-}
-lean_ctor_set(x_99, 0, x_97);
-if (lean_is_scalar(x_96)) {
- x_100 = lean_alloc_ctor(0, 2, 0);
-} else {
- x_100 = x_96;
-}
-lean_ctor_set(x_100, 0, x_99);
-lean_ctor_set(x_100, 1, x_95);
-return x_100;
-}
-}
-case 7:
-{
-lean_object* x_101; lean_object* x_102; lean_object* x_103; lean_object* x_104; 
-x_101 = lean_ctor_get(x_2, 1);
-lean_inc(x_101);
-x_102 = lean_ctor_get(x_2, 2);
-lean_inc(x_102);
-lean_dec(x_2);
-lean_inc(x_1);
-x_103 = l_Lean_Expr_FindExtImpl_findM_x3f_visit(x_1, x_101, x_5);
-x_104 = lean_ctor_get(x_103, 0);
-lean_inc(x_104);
-if (lean_obj_tag(x_104) == 0)
-{
-lean_object* x_105; 
-x_105 = lean_ctor_get(x_103, 1);
-lean_inc(x_105);
-lean_dec(x_103);
-x_2 = x_102;
-x_3 = x_105;
-goto _start;
-}
-else
-{
-lean_object* x_107; lean_object* x_108; lean_object* x_109; lean_object* x_110; lean_object* x_111; lean_object* x_112; 
-lean_dec(x_102);
-lean_dec(x_1);
-x_107 = lean_ctor_get(x_103, 1);
-lean_inc(x_107);
-if (lean_is_exclusive(x_103)) {
- lean_ctor_release(x_103, 0);
- lean_ctor_release(x_103, 1);
- x_108 = x_103;
-} else {
- lean_dec_ref(x_103);
- x_108 = lean_box(0);
-}
-x_109 = lean_ctor_get(x_104, 0);
-lean_inc(x_109);
-if (lean_is_exclusive(x_104)) {
- lean_ctor_release(x_104, 0);
- x_110 = x_104;
-} else {
- lean_dec_ref(x_104);
- x_110 = lean_box(0);
-}
-if (lean_is_scalar(x_110)) {
- x_111 = lean_alloc_ctor(1, 1, 0);
-} else {
- x_111 = x_110;
-}
-lean_ctor_set(x_111, 0, x_109);
-if (lean_is_scalar(x_108)) {
- x_112 = lean_alloc_ctor(0, 2, 0);
-} else {
- x_112 = x_108;
-}
-lean_ctor_set(x_112, 0, x_111);
-lean_ctor_set(x_112, 1, x_107);
-return x_112;
-}
-}
-case 8:
-{
-lean_object* x_113; lean_object* x_114; lean_object* x_115; lean_object* x_116; lean_object* x_117; 
-x_113 = lean_ctor_get(x_2, 1);
-lean_inc(x_113);
-x_114 = lean_ctor_get(x_2, 2);
-lean_inc(x_114);
-x_115 = lean_ctor_get(x_2, 3);
-lean_inc(x_115);
-lean_dec(x_2);
-lean_inc(x_1);
-x_116 = l_Lean_Expr_FindExtImpl_findM_x3f_visit(x_1, x_113, x_5);
-x_117 = lean_ctor_get(x_116, 0);
-lean_inc(x_117);
-if (lean_obj_tag(x_117) == 0)
-{
-lean_object* x_118; lean_object* x_119; lean_object* x_120; 
-x_118 = lean_ctor_get(x_116, 1);
-lean_inc(x_118);
-lean_dec(x_116);
-lean_inc(x_1);
-x_119 = l_Lean_Expr_FindExtImpl_findM_x3f_visit(x_1, x_114, x_118);
-x_120 = lean_ctor_get(x_119, 0);
-lean_inc(x_120);
-if (lean_obj_tag(x_120) == 0)
-{
-lean_object* x_121; 
-x_121 = lean_ctor_get(x_119, 1);
-lean_inc(x_121);
-lean_dec(x_119);
-x_2 = x_115;
-x_3 = x_121;
-goto _start;
-}
-else
-{
-lean_object* x_123; lean_object* x_124; lean_object* x_125; lean_object* x_126; lean_object* x_127; lean_object* x_128; 
-lean_dec(x_115);
-lean_dec(x_1);
-x_123 = lean_ctor_get(x_119, 1);
-lean_inc(x_123);
-if (lean_is_exclusive(x_119)) {
- lean_ctor_release(x_119, 0);
- lean_ctor_release(x_119, 1);
- x_124 = x_119;
-} else {
- lean_dec_ref(x_119);
- x_124 = lean_box(0);
-}
-x_125 = lean_ctor_get(x_120, 0);
-lean_inc(x_125);
-if (lean_is_exclusive(x_120)) {
- lean_ctor_release(x_120, 0);
- x_126 = x_120;
-} else {
- lean_dec_ref(x_120);
- x_126 = lean_box(0);
-}
-if (lean_is_scalar(x_126)) {
- x_127 = lean_alloc_ctor(1, 1, 0);
-} else {
- x_127 = x_126;
-}
-lean_ctor_set(x_127, 0, x_125);
-if (lean_is_scalar(x_124)) {
- x_128 = lean_alloc_ctor(0, 2, 0);
-} else {
- x_128 = x_124;
-}
-lean_ctor_set(x_128, 0, x_127);
-lean_ctor_set(x_128, 1, x_123);
-return x_128;
-}
-}
-else
-{
-lean_object* x_129; lean_object* x_130; lean_object* x_131; lean_object* x_132; lean_object* x_133; lean_object* x_134; 
-lean_dec(x_115);
-lean_dec(x_114);
-lean_dec(x_1);
-x_129 = lean_ctor_get(x_116, 1);
-lean_inc(x_129);
-if (lean_is_exclusive(x_116)) {
- lean_ctor_release(x_116, 0);
- lean_ctor_release(x_116, 1);
- x_130 = x_116;
-} else {
- lean_dec_ref(x_116);
- x_130 = lean_box(0);
-}
-x_131 = lean_ctor_get(x_117, 0);
-lean_inc(x_131);
-if (lean_is_exclusive(x_117)) {
- lean_ctor_release(x_117, 0);
- x_132 = x_117;
-} else {
- lean_dec_ref(x_117);
- x_132 = lean_box(0);
-}
-if (lean_is_scalar(x_132)) {
- x_133 = lean_alloc_ctor(1, 1, 0);
-} else {
- x_133 = x_132;
-}
-lean_ctor_set(x_133, 0, x_131);
-if (lean_is_scalar(x_130)) {
- x_134 = lean_alloc_ctor(0, 2, 0);
-} else {
- x_134 = x_130;
-}
-lean_ctor_set(x_134, 0, x_133);
-lean_ctor_set(x_134, 1, x_129);
-return x_134;
-}
-}
-case 10:
-{
-lean_object* x_135; 
-x_135 = lean_ctor_get(x_2, 1);
-lean_inc(x_135);
-lean_dec(x_2);
-x_2 = x_135;
-x_3 = x_5;
-goto _start;
-}
-case 11:
-{
-lean_object* x_137; 
-x_137 = lean_ctor_get(x_2, 2);
-lean_inc(x_137);
-lean_dec(x_2);
-x_2 = x_137;
-x_3 = x_5;
-goto _start;
-}
-default: 
-{
-lean_object* x_139; lean_object* x_140; 
-lean_dec(x_2);
-lean_dec(x_1);
-x_139 = lean_box(0);
-x_140 = lean_alloc_ctor(0, 2, 0);
-lean_ctor_set(x_140, 0, x_139);
-lean_ctor_set(x_140, 1, x_5);
-return x_140;
-}
-}
-}
-default: 
-{
-lean_object* x_141; lean_object* x_142; 
-lean_dec(x_2);
-lean_dec(x_1);
-x_141 = lean_box(0);
-x_142 = lean_alloc_ctor(0, 2, 0);
-lean_ctor_set(x_142, 0, x_141);
-lean_ctor_set(x_142, 1, x_5);
-return x_142;
-}
-}
-}
-}
-}
-}
-}
-LEAN_EXPORT lean_object* l_Lean_Expr_FindExtImpl_findM_x3f(lean_object* x_1, lean_object* x_2, lean_object* x_3) {
-_start:
-{
-lean_object* x_4; 
-x_4 = l_Lean_Expr_FindExtImpl_findM_x3f_visit(x_1, x_2, x_3);
-return x_4;
-}
-}
-LEAN_EXPORT lean_object* l_Lean_Expr_FindExtImpl_findUnsafe_x3f(lean_object* x_1, lean_object* x_2) {
-_start:
-{
-lean_object* x_3; lean_object* x_4; lean_object* x_5; 
-x_3 = l_Lean_Expr_FindImpl_findUnsafe_x3f___closed__1;
-x_4 = l_Lean_Expr_FindExtImpl_findM_x3f_visit(x_1, x_2, x_3);
-x_5 = lean_ctor_get(x_4, 0);
-lean_inc(x_5);
-lean_dec(x_4);
-return x_5;
+return x_3;
 }
 }
 lean_object* initialize_Lean_Expr(uint8_t builtin, lean_object*);
@@ -2452,10 +242,6 @@ lean_dec_ref(res);
 res = initialize_Lean_Util_PtrSet(builtin, lean_io_mk_world());
 if (lean_io_result_is_error(res)) return res;
 lean_dec_ref(res);
-l_Lean_Expr_FindImpl_checkVisited___lambda__1___closed__1 = _init_l_Lean_Expr_FindImpl_checkVisited___lambda__1___closed__1();
-lean_mark_persistent(l_Lean_Expr_FindImpl_checkVisited___lambda__1___closed__1);
-l_Lean_Expr_FindImpl_findUnsafe_x3f___closed__1 = _init_l_Lean_Expr_FindImpl_findUnsafe_x3f___closed__1();
-lean_mark_persistent(l_Lean_Expr_FindImpl_findUnsafe_x3f___closed__1);
 l_Lean_Expr_FindStep_noConfusion___rarg___closed__1 = _init_l_Lean_Expr_FindStep_noConfusion___rarg___closed__1();
 lean_mark_persistent(l_Lean_Expr_FindStep_noConfusion___rarg___closed__1);
 return lean_io_result_mk_ok(lean_box(0));
diff --git a/stage0/stdlib/Lean/Util/ReplaceExpr.c b/stage0/stdlib/Lean/Util/ReplaceExpr.c
index 7d5cf8760c..81c9fe8ccd 100644
--- a/stage0/stdlib/Lean/Util/ReplaceExpr.c
+++ b/stage0/stdlib/Lean/Util/ReplaceExpr.c
@@ -31,7 +31,9 @@ LEAN_EXPORT lean_object* l_Lean_Expr_ReplaceImpl_cache(lean_object*, uint8_t, le
 LEAN_EXPORT lean_object* l_Lean_Expr_ReplaceImpl_replaceUnsafe(lean_object*, lean_object*);
 size_t lean_ptr_addr(lean_object*);
 uint8_t lean_is_exclusive_obj(lean_object*);
+lean_object* lean_replace_expr(lean_object*, lean_object*);
 uint64_t lean_usize_to_uint64(size_t);
+LEAN_EXPORT lean_object* l_Lean_Expr_replaceImpl___boxed(lean_object*, lean_object*);
 lean_object* l_Lean_Expr_forallE___override(lean_object*, lean_object*, lean_object*, uint8_t);
 LEAN_EXPORT lean_object* l_Lean_Expr_ReplaceImpl_cache___boxed(lean_object*, lean_object*, lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_AssocList_contains___at_Lean_Expr_ReplaceImpl_cache___spec__2___boxed(lean_object*, lean_object*);
@@ -1380,6 +1382,16 @@ return x_85;
 }
 }
 }
+LEAN_EXPORT lean_object* l_Lean_Expr_replaceImpl___boxed(lean_object* x_1, lean_object* x_2) {
+_start:
+{
+lean_object* x_3; 
+x_3 = lean_replace_expr(x_1, x_2);
+lean_dec(x_2);
+lean_dec(x_1);
+return x_3;
+}
+}
 lean_object* initialize_Lean_Expr(uint8_t builtin, lean_object*);
 lean_object* initialize_Lean_Util_PtrSet(uint8_t builtin, lean_object*);
 static bool _G_initialized = false;
diff --git a/stage0/stdlib/Lean/Util/Sorry.c b/stage0/stdlib/Lean/Util/Sorry.c
index 8df55905f7..99baea4f63 100644
--- a/stage0/stdlib/Lean/Util/Sorry.c
+++ b/stage0/stdlib/Lean/Util/Sorry.c
@@ -42,7 +42,6 @@ LEAN_EXPORT lean_object* l_List_foldlM___at_Lean_Declaration_hasSorry___spec__4_
 lean_object* l_Lean_Name_str___override(lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_List_foldlM___at_Lean_Declaration_hasNonSyntheticSorry___spec__2___boxed(lean_object*, lean_object*);
 static lean_object* l_Lean_Expr_isSyntheticSorry___closed__2;
-lean_object* l_Lean_Expr_FindImpl_findUnsafe_x3f(lean_object*, lean_object*);
 LEAN_EXPORT uint8_t l_Lean_Declaration_foldExprM___at_Lean_Declaration_hasNonSyntheticSorry___spec__1(lean_object*, uint8_t);
 LEAN_EXPORT lean_object* l_List_foldlM___at_Lean_Declaration_hasSorry___spec__3___boxed(lean_object*, lean_object*);
 uint8_t l_Lean_Expr_isConstOf(lean_object*, lean_object*);
@@ -53,6 +52,7 @@ LEAN_EXPORT uint8_t l_List_foldlM___at_Lean_Declaration_hasNonSyntheticSorry___s
 LEAN_EXPORT lean_object* l_Lean_Expr_hasSorry___lambda__1___boxed(lean_object*);
 LEAN_EXPORT uint8_t l_Lean_Expr_hasNonSyntheticSorry(lean_object*);
 LEAN_EXPORT uint8_t l_List_foldlM___at_Lean_Declaration_hasSorry___spec__2(uint8_t, lean_object*);
+lean_object* lean_find_expr(lean_object*, lean_object*);
 LEAN_EXPORT uint8_t l_List_foldlM___at_Lean_Declaration_hasSorry___spec__3(uint8_t, lean_object*);
 LEAN_EXPORT lean_object* l_List_foldlM___at_Lean_Declaration_hasNonSyntheticSorry___spec__4___boxed(lean_object*, lean_object*);
 LEAN_EXPORT lean_object* l_Lean_Expr_hasNonSyntheticSorry___boxed(lean_object*);
@@ -480,7 +480,7 @@ _start:
 {
 lean_object* x_2; lean_object* x_3; 
 x_2 = l_Lean_Expr_hasSorry___closed__1;
-x_3 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_2, x_1);
+x_3 = lean_find_expr(x_2, x_1);
 if (lean_obj_tag(x_3) == 0)
 {
 uint8_t x_4; 
@@ -511,6 +511,7 @@ _start:
 {
 uint8_t x_2; lean_object* x_3; 
 x_2 = l_Lean_Expr_hasSorry(x_1);
+lean_dec(x_1);
 x_3 = lean_box(x_2);
 return x_3;
 }
@@ -528,7 +529,7 @@ _start:
 {
 lean_object* x_2; lean_object* x_3; 
 x_2 = l_Lean_Expr_hasSyntheticSorry___closed__1;
-x_3 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_2, x_1);
+x_3 = lean_find_expr(x_2, x_1);
 if (lean_obj_tag(x_3) == 0)
 {
 uint8_t x_4; 
@@ -549,6 +550,7 @@ _start:
 {
 uint8_t x_2; lean_object* x_3; 
 x_2 = l_Lean_Expr_hasSyntheticSorry(x_1);
+lean_dec(x_1);
 x_3 = lean_box(x_2);
 return x_3;
 }
@@ -566,7 +568,7 @@ _start:
 {
 lean_object* x_2; lean_object* x_3; 
 x_2 = l_Lean_Expr_hasNonSyntheticSorry___closed__1;
-x_3 = l_Lean_Expr_FindImpl_findUnsafe_x3f(x_2, x_1);
+x_3 = lean_find_expr(x_2, x_1);
 if (lean_obj_tag(x_3) == 0)
 {
 uint8_t x_4; 
@@ -587,6 +589,7 @@ _start:
 {
 uint8_t x_2; lean_object* x_3; 
 x_2 = l_Lean_Expr_hasNonSyntheticSorry(x_1);
+lean_dec(x_1);
 x_3 = lean_box(x_2);
 return x_3;
 }
@@ -604,22 +607,14 @@ if (x_1 == 0)
 {
 lean_object* x_3; lean_object* x_4; lean_object* x_5; lean_object* x_6; uint8_t x_7; 
 x_3 = lean_ctor_get(x_2, 0);
-lean_inc(x_3);
 x_4 = lean_ctor_get(x_2, 1);
-lean_inc(x_4);
-lean_dec(x_2);
 x_5 = lean_ctor_get(x_3, 0);
-lean_inc(x_5);
 x_6 = lean_ctor_get(x_5, 2);
-lean_inc(x_6);
-lean_dec(x_5);
 x_7 = l_Lean_Expr_hasSorry(x_6);
 if (x_7 == 0)
 {
 lean_object* x_8; uint8_t x_9; 
 x_8 = lean_ctor_get(x_3, 1);
-lean_inc(x_8);
-lean_dec(x_3);
 x_9 = l_Lean_Expr_hasSorry(x_8);
 x_1 = x_9;
 x_2 = x_4;
@@ -628,7 +623,6 @@ goto _start;
 else
 {
 uint8_t x_11; 
-lean_dec(x_3);
 x_11 = 1;
 x_1 = x_11;
 x_2 = x_4;
@@ -639,8 +633,6 @@ else
 {
 lean_object* x_13; uint8_t x_14; 
 x_13 = lean_ctor_get(x_2, 1);
-lean_inc(x_13);
-lean_dec(x_2);
 x_14 = 1;
 x_1 = x_14;
 x_2 = x_13;
@@ -662,13 +654,8 @@ if (x_1 == 0)
 {
 lean_object* x_3; lean_object* x_4; lean_object* x_5; uint8_t x_6; 
 x_3 = lean_ctor_get(x_2, 0);
-lean_inc(x_3);
 x_4 = lean_ctor_get(x_2, 1);
-lean_inc(x_4);
-lean_dec(x_2);
 x_5 = lean_ctor_get(x_3, 1);
-lean_inc(x_5);
-lean_dec(x_3);
 x_6 = l_Lean_Expr_hasSorry(x_5);
 x_1 = x_6;
 x_2 = x_4;
@@ -678,8 +665,6 @@ else
 {
 lean_object* x_8; uint8_t x_9; 
 x_8 = lean_ctor_get(x_2, 1);
-lean_inc(x_8);
-lean_dec(x_2);
 x_9 = 1;
 x_1 = x_9;
 x_2 = x_8;
@@ -701,15 +686,9 @@ if (x_1 == 0)
 {
 lean_object* x_3; lean_object* x_4; lean_object* x_5; lean_object* x_6; uint8_t x_7; uint8_t x_8; 
 x_3 = lean_ctor_get(x_2, 0);
-lean_inc(x_3);
 x_4 = lean_ctor_get(x_2, 1);
-lean_inc(x_4);
-lean_dec(x_2);
 x_5 = lean_ctor_get(x_3, 2);
-lean_inc(x_5);
 x_6 = lean_ctor_get(x_3, 1);
-lean_inc(x_6);
-lean_dec(x_3);
 x_7 = l_Lean_Expr_hasSorry(x_6);
 x_8 = l_List_foldlM___at_Lean_Declaration_hasSorry___spec__3(x_7, x_5);
 x_1 = x_8;
@@ -720,13 +699,8 @@ else
 {
 lean_object* x_10; lean_object* x_11; lean_object* x_12; uint8_t x_13; uint8_t x_14; 
 x_10 = lean_ctor_get(x_2, 0);
-lean_inc(x_10);
 x_11 = lean_ctor_get(x_2, 1);
-lean_inc(x_11);
-lean_dec(x_2);
 x_12 = lean_ctor_get(x_10, 2);
-lean_inc(x_12);
-lean_dec(x_10);
 x_13 = 1;
 x_14 = l_List_foldlM___at_Lean_Declaration_hasSorry___spec__3(x_13, x_12);
 x_1 = x_14;
@@ -742,26 +716,18 @@ _start:
 switch (lean_obj_tag(x_1)) {
 case 0:
 {
-lean_object* x_3; lean_object* x_4; 
-x_3 = lean_ctor_get(x_1, 0);
-lean_inc(x_3);
-lean_dec(x_1);
-x_4 = lean_ctor_get(x_3, 0);
-lean_inc(x_4);
-lean_dec(x_3);
 if (x_2 == 0)
 {
-lean_object* x_5; uint8_t x_6; 
+lean_object* x_3; lean_object* x_4; lean_object* x_5; uint8_t x_6; 
+x_3 = lean_ctor_get(x_1, 0);
+x_4 = lean_ctor_get(x_3, 0);
 x_5 = lean_ctor_get(x_4, 2);
-lean_inc(x_5);
-lean_dec(x_4);
 x_6 = l_Lean_Expr_hasSorry(x_5);
 return x_6;
 }
 else
 {
 uint8_t x_7; 
-lean_dec(x_4);
 x_7 = 1;
 return x_7;
 }
@@ -774,8 +740,6 @@ case 5:
 {
 lean_object* x_8; uint8_t x_9; 
 x_8 = lean_ctor_get(x_1, 0);
-lean_inc(x_8);
-lean_dec(x_1);
 x_9 = l_List_foldlM___at_Lean_Declaration_hasSorry___spec__2(x_2, x_8);
 return x_9;
 }
@@ -783,28 +747,18 @@ case 6:
 {
 lean_object* x_10; uint8_t x_11; 
 x_10 = lean_ctor_get(x_1, 2);
-lean_inc(x_10);
-lean_dec(x_1);
 x_11 = l_List_foldlM___at_Lean_Declaration_hasSorry___spec__4(x_2, x_10);
 return x_11;
 }
 default: 
 {
-lean_object* x_12; lean_object* x_13; 
-x_12 = lean_ctor_get(x_1, 0);
-lean_inc(x_12);
-lean_dec(x_1);
-x_13 = lean_ctor_get(x_12, 0);
-lean_inc(x_13);
 if (x_2 == 0)
 {
-lean_object* x_14; lean_object* x_15; uint8_t x_16; 
+lean_object* x_12; lean_object* x_13; lean_object* x_14; lean_object* x_15; uint8_t x_16; 
+x_12 = lean_ctor_get(x_1, 0);
+x_13 = lean_ctor_get(x_12, 0);
 x_14 = lean_ctor_get(x_12, 1);
-lean_inc(x_14);
-lean_dec(x_12);
 x_15 = lean_ctor_get(x_13, 2);
-lean_inc(x_15);
-lean_dec(x_13);
 x_16 = l_Lean_Expr_hasSorry(x_15);
 if (x_16 == 0)
 {
@@ -815,7 +769,6 @@ return x_17;
 else
 {
 uint8_t x_18; 
-lean_dec(x_14);
 x_18 = 1;
 return x_18;
 }
@@ -823,8 +776,6 @@ return x_18;
 else
 {
 uint8_t x_19; 
-lean_dec(x_13);
-lean_dec(x_12);
 x_19 = 1;
 return x_19;
 }
@@ -848,6 +799,7 @@ uint8_t x_3; uint8_t x_4; lean_object* x_5;
 x_3 = lean_unbox(x_1);
 lean_dec(x_1);
 x_4 = l_List_foldlM___at_Lean_Declaration_hasSorry___spec__2(x_3, x_2);
+lean_dec(x_2);
 x_5 = lean_box(x_4);
 return x_5;
 }
@@ -859,6 +811,7 @@ uint8_t x_3; uint8_t x_4; lean_object* x_5;
 x_3 = lean_unbox(x_1);
 lean_dec(x_1);
 x_4 = l_List_foldlM___at_Lean_Declaration_hasSorry___spec__3(x_3, x_2);
+lean_dec(x_2);
 x_5 = lean_box(x_4);
 return x_5;
 }
@@ -870,6 +823,7 @@ uint8_t x_3; uint8_t x_4; lean_object* x_5;
 x_3 = lean_unbox(x_1);
 lean_dec(x_1);
 x_4 = l_List_foldlM___at_Lean_Declaration_hasSorry___spec__4(x_3, x_2);
+lean_dec(x_2);
 x_5 = lean_box(x_4);
 return x_5;
 }
@@ -881,6 +835,7 @@ uint8_t x_3; uint8_t x_4; lean_object* x_5;
 x_3 = lean_unbox(x_2);
 lean_dec(x_2);
 x_4 = l_Lean_Declaration_foldExprM___at_Lean_Declaration_hasSorry___spec__1(x_1, x_3);
+lean_dec(x_1);
 x_5 = lean_box(x_4);
 return x_5;
 }
@@ -890,6 +845,7 @@ _start:
 {
 uint8_t x_2; lean_object* x_3; 
 x_2 = l_Lean_Declaration_hasSorry(x_1);
+lean_dec(x_1);
 x_3 = lean_box(x_2);
 return x_3;
 }
@@ -907,22 +863,14 @@ if (x_1 == 0)
 {
 lean_object* x_3; lean_object* x_4; lean_object* x_5; lean_object* x_6; uint8_t x_7; 
 x_3 = lean_ctor_get(x_2, 0);
-lean_inc(x_3);
 x_4 = lean_ctor_get(x_2, 1);
-lean_inc(x_4);
-lean_dec(x_2);
 x_5 = lean_ctor_get(x_3, 0);
-lean_inc(x_5);
 x_6 = lean_ctor_get(x_5, 2);
-lean_inc(x_6);
-lean_dec(x_5);
 x_7 = l_Lean_Expr_hasNonSyntheticSorry(x_6);
 if (x_7 == 0)
 {
 lean_object* x_8; uint8_t x_9; 
 x_8 = lean_ctor_get(x_3, 1);
-lean_inc(x_8);
-lean_dec(x_3);
 x_9 = l_Lean_Expr_hasNonSyntheticSorry(x_8);
 x_1 = x_9;
 x_2 = x_4;
@@ -931,7 +879,6 @@ goto _start;
 else
 {
 uint8_t x_11; 
-lean_dec(x_3);
 x_11 = 1;
 x_1 = x_11;
 x_2 = x_4;
@@ -942,8 +889,6 @@ else
 {
 lean_object* x_13; uint8_t x_14; 
 x_13 = lean_ctor_get(x_2, 1);
-lean_inc(x_13);
-lean_dec(x_2);
 x_14 = 1;
 x_1 = x_14;
 x_2 = x_13;
@@ -965,13 +910,8 @@ if (x_1 == 0)
 {
 lean_object* x_3; lean_object* x_4; lean_object* x_5; uint8_t x_6; 
 x_3 = lean_ctor_get(x_2, 0);
-lean_inc(x_3);
 x_4 = lean_ctor_get(x_2, 1);
-lean_inc(x_4);
-lean_dec(x_2);
 x_5 = lean_ctor_get(x_3, 1);
-lean_inc(x_5);
-lean_dec(x_3);
 x_6 = l_Lean_Expr_hasNonSyntheticSorry(x_5);
 x_1 = x_6;
 x_2 = x_4;
@@ -981,8 +921,6 @@ else
 {
 lean_object* x_8; uint8_t x_9; 
 x_8 = lean_ctor_get(x_2, 1);
-lean_inc(x_8);
-lean_dec(x_2);
 x_9 = 1;
 x_1 = x_9;
 x_2 = x_8;
@@ -1004,15 +942,9 @@ if (x_1 == 0)
 {
 lean_object* x_3; lean_object* x_4; lean_object* x_5; lean_object* x_6; uint8_t x_7; uint8_t x_8; 
 x_3 = lean_ctor_get(x_2, 0);
-lean_inc(x_3);
 x_4 = lean_ctor_get(x_2, 1);
-lean_inc(x_4);
-lean_dec(x_2);
 x_5 = lean_ctor_get(x_3, 2);
-lean_inc(x_5);
 x_6 = lean_ctor_get(x_3, 1);
-lean_inc(x_6);
-lean_dec(x_3);
 x_7 = l_Lean_Expr_hasNonSyntheticSorry(x_6);
 x_8 = l_List_foldlM___at_Lean_Declaration_hasNonSyntheticSorry___spec__3(x_7, x_5);
 x_1 = x_8;
@@ -1023,13 +955,8 @@ else
 {
 lean_object* x_10; lean_object* x_11; lean_object* x_12; uint8_t x_13; uint8_t x_14; 
 x_10 = lean_ctor_get(x_2, 0);
-lean_inc(x_10);
 x_11 = lean_ctor_get(x_2, 1);
-lean_inc(x_11);
-lean_dec(x_2);
 x_12 = lean_ctor_get(x_10, 2);
-lean_inc(x_12);
-lean_dec(x_10);
 x_13 = 1;
 x_14 = l_List_foldlM___at_Lean_Declaration_hasNonSyntheticSorry___spec__3(x_13, x_12);
 x_1 = x_14;
@@ -1045,26 +972,18 @@ _start:
 switch (lean_obj_tag(x_1)) {
 case 0:
 {
-lean_object* x_3; lean_object* x_4; 
-x_3 = lean_ctor_get(x_1, 0);
-lean_inc(x_3);
-lean_dec(x_1);
-x_4 = lean_ctor_get(x_3, 0);
-lean_inc(x_4);
-lean_dec(x_3);
 if (x_2 == 0)
 {
-lean_object* x_5; uint8_t x_6; 
+lean_object* x_3; lean_object* x_4; lean_object* x_5; uint8_t x_6; 
+x_3 = lean_ctor_get(x_1, 0);
+x_4 = lean_ctor_get(x_3, 0);
 x_5 = lean_ctor_get(x_4, 2);
-lean_inc(x_5);
-lean_dec(x_4);
 x_6 = l_Lean_Expr_hasNonSyntheticSorry(x_5);
 return x_6;
 }
 else
 {
 uint8_t x_7; 
-lean_dec(x_4);
 x_7 = 1;
 return x_7;
 }
@@ -1077,8 +996,6 @@ case 5:
 {
 lean_object* x_8; uint8_t x_9; 
 x_8 = lean_ctor_get(x_1, 0);
-lean_inc(x_8);
-lean_dec(x_1);
 x_9 = l_List_foldlM___at_Lean_Declaration_hasNonSyntheticSorry___spec__2(x_2, x_8);
 return x_9;
 }
@@ -1086,28 +1003,18 @@ case 6:
 {
 lean_object* x_10; uint8_t x_11; 
 x_10 = lean_ctor_get(x_1, 2);
-lean_inc(x_10);
-lean_dec(x_1);
 x_11 = l_List_foldlM___at_Lean_Declaration_hasNonSyntheticSorry___spec__4(x_2, x_10);
 return x_11;
 }
 default: 
 {
-lean_object* x_12; lean_object* x_13; 
-x_12 = lean_ctor_get(x_1, 0);
-lean_inc(x_12);
-lean_dec(x_1);
-x_13 = lean_ctor_get(x_12, 0);
-lean_inc(x_13);
 if (x_2 == 0)
 {
-lean_object* x_14; lean_object* x_15; uint8_t x_16; 
+lean_object* x_12; lean_object* x_13; lean_object* x_14; lean_object* x_15; uint8_t x_16; 
+x_12 = lean_ctor_get(x_1, 0);
+x_13 = lean_ctor_get(x_12, 0);
 x_14 = lean_ctor_get(x_12, 1);
-lean_inc(x_14);
-lean_dec(x_12);
 x_15 = lean_ctor_get(x_13, 2);
-lean_inc(x_15);
-lean_dec(x_13);
 x_16 = l_Lean_Expr_hasNonSyntheticSorry(x_15);
 if (x_16 == 0)
 {
@@ -1118,7 +1025,6 @@ return x_17;
 else
 {
 uint8_t x_18; 
-lean_dec(x_14);
 x_18 = 1;
 return x_18;
 }
@@ -1126,8 +1032,6 @@ return x_18;
 else
 {
 uint8_t x_19; 
-lean_dec(x_13);
-lean_dec(x_12);
 x_19 = 1;
 return x_19;
 }
@@ -1151,6 +1055,7 @@ uint8_t x_3; uint8_t x_4; lean_object* x_5;
 x_3 = lean_unbox(x_1);
 lean_dec(x_1);
 x_4 = l_List_foldlM___at_Lean_Declaration_hasNonSyntheticSorry___spec__2(x_3, x_2);
+lean_dec(x_2);
 x_5 = lean_box(x_4);
 return x_5;
 }
@@ -1162,6 +1067,7 @@ uint8_t x_3; uint8_t x_4; lean_object* x_5;
 x_3 = lean_unbox(x_1);
 lean_dec(x_1);
 x_4 = l_List_foldlM___at_Lean_Declaration_hasNonSyntheticSorry___spec__3(x_3, x_2);
+lean_dec(x_2);
 x_5 = lean_box(x_4);
 return x_5;
 }
@@ -1173,6 +1079,7 @@ uint8_t x_3; uint8_t x_4; lean_object* x_5;
 x_3 = lean_unbox(x_1);
 lean_dec(x_1);
 x_4 = l_List_foldlM___at_Lean_Declaration_hasNonSyntheticSorry___spec__4(x_3, x_2);
+lean_dec(x_2);
 x_5 = lean_box(x_4);
 return x_5;
 }
@@ -1184,6 +1091,7 @@ uint8_t x_3; uint8_t x_4; lean_object* x_5;
 x_3 = lean_unbox(x_2);
 lean_dec(x_2);
 x_4 = l_Lean_Declaration_foldExprM___at_Lean_Declaration_hasNonSyntheticSorry___spec__1(x_1, x_3);
+lean_dec(x_1);
 x_5 = lean_box(x_4);
 return x_5;
 }
@@ -1193,6 +1101,7 @@ _start:
 {
 uint8_t x_2; lean_object* x_3; 
 x_2 = l_Lean_Declaration_hasNonSyntheticSorry(x_1);
+lean_dec(x_1);
 x_3 = lean_box(x_2);
 return x_3;
 }