diff --git a/script/apply.lean b/script/apply.lean
index 896d3a6b22..70bf754cde 100644
--- a/script/apply.lean
+++ b/script/apply.lean
@@ -14,7 +14,7 @@ def emit (s : String) : M Unit := do
 def mkTypedefFn (i : Nat) : M Unit := do
   let args := (List.replicate i "obj*").intersperse ", " |> String.join
   emit s!"typedef obj* (*fn{i})({args}); // NOLINT\n"
-  emit s!"#define FN{i}(f) reinterpret_cast<fn{i}>(closure_fun(f))\n"
+  emit s!"#define FN{i}(f) reinterpret_cast<fn{i}>(lean_closure_fun(f))\n"
 
 def genSeq (n : Nat) (f : Nat → String) (sep := ", ") : String := 
   List.range n |>.map f |>.intersperse sep |> .join
@@ -32,105 +32,107 @@ def mkArgs (n : Nat) : String := mkArgsFrom 0 n
 
 -- make string: "as[0], as[1], ..., as[n-1]"
 def mkAsArgs (n : Nat) : String :=
-  genSeq n (s!"a[{·}]")
+  genSeq n (s!"as[{·}]")
 
 -- make string: "fx(0), ..., fx(n-1)"
 def mkFsArgs (n : Nat) : String :=
   genSeq n (s!"fx({·})")
 
--- make string: "inc(fx(0)); ...; inc(fx(n-1))"
+-- make string: "lean_inc(fx(0)); ...; lean_inc(fx(n-1))"
 def mkIncFs (n : Nat) : String :=
-  genSeq n (s!"inc(fx({·}))") (sep := "; ")
+  genSeq n (s!"lean_inc(fx({·})); ") (sep := "")
 
 def mkApplyI (n : Nat) (max : Nat) : M Unit := do
   let argDecls := mkArgDecls n
   let args := mkArgs n
-  emit s!"obj* apply_{n}(obj* f, {argDecls}) \{
-unsigned arity = closure_arity(f);
-unsigned fixed = closure_num_fixed(f);
+  emit s!"extern \"C\" LEAN_EXPORT obj* lean_apply_{n}(obj* f, {argDecls}) \{
+if (lean_is_scalar(f)) \{ {genSeq n (s!"lean_dec(a{·+1}); ") (sep := "")}return f; } // f is an erased proof
+unsigned arity = lean_closure_arity(f);
+unsigned fixed = lean_closure_num_fixed(f);
 if (arity == fixed + {n}) \{
-  if (is_exclusive(f)) \{
+  if (lean_is_exclusive(f)) \{
     switch (arity) \{\n"
   for j in [n:max + 1] do
     let fs := mkFsArgs (j - n)
     let sep := if j = n then "" else ", "
-    emit s!"    case {j}: \{ obj* r = FN{j}(f)({fs}{sep}{args}); free_closure_obj(f); return r; }\n"
+    emit s!"    case {j}: \{ obj* r = FN{j}(f)({fs}{sep}{args}); lean_free_small_object(f); return r; }\n"
   emit "    }
   }
   switch (arity) {\n"
   for j in [n:max + 1] do
-    let incfs := mkIncFs (j - n)
+    let lean_incfs := mkIncFs (j - n)
     let fs := mkFsArgs (j - n)
     let sep := if j = n then "" else ", "
-    emit  s!"  case {j}: \{ {incfs}obj* r = FN{j}(f)({fs}{sep}{args}); dec_ref(f); return r; }\n"
+    emit  s!"  case {j}: \{ {lean_incfs}obj* r = FN{j}(f)({fs}{sep}{args}); lean_dec_ref(f); return r; }\n"
   emit s!"  default:
     lean_assert(arity > {max});
     obj * as[{n}] = \{ {args} };
     obj ** args = static_cast<obj**>(LEAN_ALLOCA(arity*sizeof(obj*))); // NOLINT
-    for (unsigned i = 0; i < fixed; i++) \{ inc(fx(i)); args[i] = fx(i); }
+    for (unsigned i = 0; i < fixed; i++) \{ lean_inc(fx(i)); args[i] = fx(i); }
     for (unsigned i = 0; i < {n}; i++) args[fixed+i] = as[i];
     obj * r = FNN(f)(args);
-    dec_ref(f);
+    lean_dec_ref(f);
     return r;
   }
 } else if (arity < fixed + {n}) \{\n"
   if n ≥ 2 then do
     emit  s!"  obj * as[{n}] = \{ {args} };
   obj ** args = static_cast<obj**>(LEAN_ALLOCA(arity*sizeof(obj*))); // NOLINT
-  for (unsigned i = 0; i < fixed; i++) \{ inc(fx(i)); args[i] = fx(i); }
+  for (unsigned i = 0; i < fixed; i++) \{ lean_inc(fx(i)); args[i] = fx(i); }
   for (unsigned i = 0; i < arity-fixed; i++) args[fixed+i] = as[i];
   obj * new_f = curry(f, arity, args);
-  dec_ref(f);
-  return apply_n(new_f, {n}+fixed-arity, as+arity-fixed);\n"
+  lean_dec_ref(f);
+  return lean_apply_n(new_f, {n}+fixed-arity, &as[arity-fixed]);\n"
   else emit s!"  lean_assert(fixed < arity);
-  lean_unreachable();
-} else \{
+  lean_unreachable();\n"
+  emit s!"} else \{
   return fix_args(f, \{{args}});
 }
 }\n"
 
 def mkCurry (max : Nat) : M Unit := do
-  emit "static obj* curry(void* f, unsigned n, obj** as) {
+  emit "obj* curry(void* f, unsigned n, obj** as) {
 switch (n) {
 case 0: lean_unreachable();\n"
   for i in [0:max] do
     let as := mkAsArgs (i+1)
-    emit  s!"case {i+1}: return reinterpret_cast<fn{i+1}>(f)({as});
-default: return reinterpret_cast<fnn>(f)(as);
+    emit  s!"case {i+1}: return reinterpret_cast<fn{i+1}>(f)({as});\n"
+  emit "default: return reinterpret_cast<fnn>(f)(as);
 }
 }
-static obj* curry(obj* f, unsigned n, obj** as) \{ return curry(closure_fun(f), n, as); }\n"
+static obj* curry(obj* f, unsigned n, obj** as) { return curry(lean_closure_fun(f), n, as); }\n"
 
 def mkApplyN (max : Nat) : M Unit := do
-  emit "obj* apply_n(obj* f, unsigned n, obj** as) {
+  emit "extern \"C\" LEAN_EXPORT obj* lean_apply_n(obj* f, unsigned n, obj** as) {
 switch (n) {
 case 0: lean_unreachable();\n"
   for i in [0:max] do
     let as := mkAsArgs (i+1)
-    emit  s!"case {i+1}: return apply_{i+1}(f, {as});
-default: return apply_m(f, n, as);
+    emit  s!"case {i+1}: return lean_apply_{i+1}(f, {as});\n"
+  emit "default: return lean_apply_m(f, n, as);
 }
 }\n"
 
 def mkApplyM (max : Nat) : M Unit :=
-  emit s!"obj* apply_m(obj* f, unsigned n, obj** as) \{
+  emit s!"extern \"C\" LEAN_EXPORT obj* lean_apply_m(obj* f, unsigned n, obj** as) \{
 lean_assert(n > {max});
-unsigned arity = closure_arity(f);
-unsigned fixed = closure_num_fixed(f);
+if (lean_is_scalar(f)) \{ for (unsigned i = 0; i < n; i++) \{ lean_dec(as[i]); } return f; } // f is an erased proof
+unsigned arity = lean_closure_arity(f);
+unsigned fixed = lean_closure_num_fixed(f);
 if (arity == fixed + n) \{
   obj ** args = static_cast<obj**>(LEAN_ALLOCA(arity*sizeof(obj*))); // NOLINT
-  for (unsigned i = 0; i < fixed; i++) \{ inc(fx(i)); args[i] = fx(i); }
+  for (unsigned i = 0; i < fixed; i++) \{ lean_inc(fx(i)); args[i] = fx(i); }
   for (unsigned i = 0; i < n; i++) args[fixed+i] = as[i];
   obj * r = FNN(f)(args);
-  dec_ref(f);
+  lean_dec_ref(f);
   return r;
 } else if (arity < fixed + n) \{
   obj ** args = static_cast<obj**>(LEAN_ALLOCA(arity*sizeof(obj*))); // NOLINT
-  for (unsigned i = 0; i < fixed; i++) \{ inc(fx(i)); args[i] = fx(i); }
+  for (unsigned i = 0; i < fixed; i++) \{ lean_inc(fx(i)); args[i] = fx(i); }
   for (unsigned i = 0; i < arity-fixed; i++) args[fixed+i] = as[i];
   obj * new_f = FNN(f)(args);
-  dec_ref(f);
-  return apply_n(new_f, n+fixed-arity, as+arity-fixed);
+  lean_dec_ref(f);
+  return lean_apply_n(new_f, n+fixed-arity, &as[arity-fixed]);
 } else \{
   return fix_args(f, n, as);
 }
@@ -138,24 +140,24 @@ if (arity == fixed + n) \{
 
 def mkFixArgs : M Unit := emit "
 static obj* fix_args(obj* f, unsigned n, obj*const* as) {
-    unsigned arity = closure_arity(f);
-    unsigned fixed = closure_num_fixed(f);
+    unsigned arity = lean_closure_arity(f);
+    unsigned fixed = lean_closure_num_fixed(f);
     unsigned new_fixed = fixed + n;
     lean_assert(new_fixed < arity);
-    obj * r = alloc_closure(closure_fun(f), arity, new_fixed);
-    obj ** source = closure_arg_cptr(f);
-    obj ** target = closure_arg_cptr(r);
-    if (!is_exclusive(f)) {
+    obj * r = lean_alloc_closure(lean_closure_fun(f), arity, new_fixed);
+    obj ** source = lean_closure_arg_cptr(f);
+    obj ** target = lean_closure_arg_cptr(r);
+    if (!lean_is_exclusive(f)) {
       for (unsigned i = 0; i < fixed; i++, source++, target++) {
           *target = *source;
-          inc(*target);
+          lean_inc(*target);
       }
-      dec_ref(f);
+      lean_dec_ref(f);
     } else {
       for (unsigned i = 0; i < fixed; i++, source++, target++) {
           *target = *source;
       }
-      free_closure_obj(f);
+      lean_free_small_object(f);
     }
     for (unsigned i = 0; i < n; i++, as++, target++) {
         *target = *as;
@@ -182,40 +184,19 @@ def mkApplyCpp (max : Nat) : M Unit := do
 // Generated using script: ../../gen/apply.lean
 #include \"runtime/apply.h\"
 namespace lean {
-#define obj object
-#define fx(i) closure_arg_cptr(f)[i]\n"
+#define obj lean_object
+#define fx(i) lean_closure_arg_cptr(f)[i]\n"
   mkFixArgs
   for i in [0:max] do mkTypedefFn (i+1)
   emit "typedef obj* (*fnn)(obj**); // NOLINT
-#define FNN(f) reinterpret_cast<fnn>(closure_fun(f))\n"
+#define FNN(f) reinterpret_cast<fnn>(lean_closure_fun(f))\n"
   mkCurry max
-  emit "obj* apply_n(obj*, unsigned, obj**);\n"
+  emit "extern \"C\" obj* lean_apply_n(obj*, unsigned, obj**);\n"
   for i in [0:max] do mkApplyI (i+1) max
   mkApplyM max
   mkApplyN max
   emit "}\n"
 
--- make string: "object* a1, object* a2, ..., object** an"
-def mkArgDecls' (n : Nat) : String :=
-  genSeq n (s!"object* a{·+1}")
-
-def mkApplyH (max : Nat) : M Unit := do
-  mkCopyright
-  emit "// DO NOT EDIT, this is an automatically generated file
-// Generated using script: ../../gen/apply.lean
-#pragma once
-#include \"runtime/object.h\"
-#define LEAN_CLOSURE_MAX_ARGS {max}"
-  emit "namespace lean {\n"
-  for i in [0:max] do
-    let args := mkArgDecls' (i+1)
-    emit  s!"object* apply_{i+1}(object* f, {args});
-object* apply_n(object* f, unsigned n, object** args);
-// pre: n > {max}
-object* apply_m(object* f, unsigned n, object** args);
-}\n"
-
 -- #eval (mkApplyCpp 4).run none
 
-#eval (mkApplyCpp Lean.closureMaxArgs).run "../src/runtime/apply.cpp"
-#eval (mkApplyH Lean.closureMaxArgs).run "../src/runtime/apply.h"
+#eval (mkApplyCpp Lean.closureMaxArgs).run "src/runtime/apply.cpp"
diff --git a/src/runtime/apply.cpp b/src/runtime/apply.cpp
index ad4c2fafbc..96043510a3 100644
--- a/src/runtime/apply.cpp
+++ b/src/runtime/apply.cpp
@@ -24,7 +24,7 @@ static obj* fix_args(obj* f, unsigned n, obj*const* as) {
           *target = *source;
           lean_inc(*target);
       }
-      dec_ref(f);
+      lean_dec_ref(f);
     } else {
       for (unsigned i = 0; i < fixed; i++, source++, target++) {
           *target = *source;
@@ -103,7 +103,7 @@ if (lean_is_scalar(f)) { lean_dec(a1); return f; } // f is an erased proof
 unsigned arity = lean_closure_arity(f);
 unsigned fixed = lean_closure_num_fixed(f);
 if (arity == fixed + 1) {
-  if (is_exclusive(f)) {
+  if (lean_is_exclusive(f)) {
     switch (arity) {
     case 1: { obj* r = FN1(f)(a1); lean_free_small_object(f); return r; }
     case 2: { obj* r = FN2(f)(fx(0), a1); lean_free_small_object(f); return r; }
@@ -162,7 +162,7 @@ if (lean_is_scalar(f)) { lean_dec(a1); lean_dec(a2); return f; } // f is an eras
 unsigned arity = lean_closure_arity(f);
 unsigned fixed = lean_closure_num_fixed(f);
 if (arity == fixed + 2) {
-  if (is_exclusive(f)) {
+  if (lean_is_exclusive(f)) {
     switch (arity) {
     case 2: { obj* r = FN2(f)(a1, a2); lean_free_small_object(f); return r; }
     case 3: { obj* r = FN3(f)(fx(0), a1, a2); lean_free_small_object(f); return r; }
@@ -224,7 +224,7 @@ if (lean_is_scalar(f)) { lean_dec(a1); lean_dec(a2); lean_dec(a3); return f; } /
 unsigned arity = lean_closure_arity(f);
 unsigned fixed = lean_closure_num_fixed(f);
 if (arity == fixed + 3) {
-  if (is_exclusive(f)) {
+  if (lean_is_exclusive(f)) {
     switch (arity) {
     case 3: { obj* r = FN3(f)(a1, a2, a3); lean_free_small_object(f); return r; }
     case 4: { obj* r = FN4(f)(fx(0), a1, a2, a3); lean_free_small_object(f); return r; }
@@ -284,7 +284,7 @@ if (lean_is_scalar(f)) { lean_dec(a1); lean_dec(a2); lean_dec(a3); lean_dec(a4);
 unsigned arity = lean_closure_arity(f);
 unsigned fixed = lean_closure_num_fixed(f);
 if (arity == fixed + 4) {
-  if (is_exclusive(f)) {
+  if (lean_is_exclusive(f)) {
     switch (arity) {
     case 4: { obj* r = FN4(f)(a1, a2, a3, a4); lean_free_small_object(f); return r; }
     case 5: { obj* r = FN5(f)(fx(0), a1, a2, a3, a4); lean_free_small_object(f); return r; }
@@ -342,7 +342,7 @@ if (lean_is_scalar(f)) { lean_dec(a1); lean_dec(a2); lean_dec(a3); lean_dec(a4);
 unsigned arity = lean_closure_arity(f);
 unsigned fixed = lean_closure_num_fixed(f);
 if (arity == fixed + 5) {
-  if (is_exclusive(f)) {
+  if (lean_is_exclusive(f)) {
     switch (arity) {
     case 5: { obj* r = FN5(f)(a1, a2, a3, a4, a5); lean_free_small_object(f); return r; }
     case 6: { obj* r = FN6(f)(fx(0), a1, a2, a3, a4, a5); lean_free_small_object(f); return r; }
@@ -398,7 +398,7 @@ if (lean_is_scalar(f)) { lean_dec(a1); lean_dec(a2); lean_dec(a3); lean_dec(a4);
 unsigned arity = lean_closure_arity(f);
 unsigned fixed = lean_closure_num_fixed(f);
 if (arity == fixed + 6) {
-  if (is_exclusive(f)) {
+  if (lean_is_exclusive(f)) {
     switch (arity) {
     case 6: { obj* r = FN6(f)(a1, a2, a3, a4, a5, a6); lean_free_small_object(f); return r; }
     case 7: { obj* r = FN7(f)(fx(0), a1, a2, a3, a4, a5, a6); lean_free_small_object(f); return r; }
@@ -452,7 +452,7 @@ if (lean_is_scalar(f)) { lean_dec(a1); lean_dec(a2); lean_dec(a3); lean_dec(a4);
 unsigned arity = lean_closure_arity(f);
 unsigned fixed = lean_closure_num_fixed(f);
 if (arity == fixed + 7) {
-  if (is_exclusive(f)) {
+  if (lean_is_exclusive(f)) {
     switch (arity) {
     case 7: { obj* r = FN7(f)(a1, a2, a3, a4, a5, a6, a7); lean_free_small_object(f); return r; }
     case 8: { obj* r = FN8(f)(fx(0), a1, a2, a3, a4, a5, a6, a7); lean_free_small_object(f); return r; }
@@ -504,7 +504,7 @@ if (lean_is_scalar(f)) { lean_dec(a1); lean_dec(a2); lean_dec(a3); lean_dec(a4);
 unsigned arity = lean_closure_arity(f);
 unsigned fixed = lean_closure_num_fixed(f);
 if (arity == fixed + 8) {
-  if (is_exclusive(f)) {
+  if (lean_is_exclusive(f)) {
     switch (arity) {
     case 8: { obj* r = FN8(f)(a1, a2, a3, a4, a5, a6, a7, a8); lean_free_small_object(f); return r; }
     case 9: { obj* r = FN9(f)(fx(0), a1, a2, a3, a4, a5, a6, a7, a8); lean_free_small_object(f); return r; }
@@ -554,7 +554,7 @@ if (lean_is_scalar(f)) { lean_dec(a1); lean_dec(a2); lean_dec(a3); lean_dec(a4);
 unsigned arity = lean_closure_arity(f);
 unsigned fixed = lean_closure_num_fixed(f);
 if (arity == fixed + 9) {
-  if (is_exclusive(f)) {
+  if (lean_is_exclusive(f)) {
     switch (arity) {
     case 9: { obj* r = FN9(f)(a1, a2, a3, a4, a5, a6, a7, a8, a9); lean_free_small_object(f); return r; }
     case 10: { obj* r = FN10(f)(fx(0), a1, a2, a3, a4, a5, a6, a7, a8, a9); lean_free_small_object(f); return r; }
@@ -602,7 +602,7 @@ if (lean_is_scalar(f)) { lean_dec(a1); lean_dec(a2); lean_dec(a3); lean_dec(a4);
 unsigned arity = lean_closure_arity(f);
 unsigned fixed = lean_closure_num_fixed(f);
 if (arity == fixed + 10) {
-  if (is_exclusive(f)) {
+  if (lean_is_exclusive(f)) {
     switch (arity) {
     case 10: { obj* r = FN10(f)(a1, a2, a3, a4, a5, a6, a7, a8, a9, a10); lean_free_small_object(f); return r; }
     case 11: { obj* r = FN11(f)(fx(0), a1, a2, a3, a4, a5, a6, a7, a8, a9, a10); lean_free_small_object(f); return r; }
@@ -648,7 +648,7 @@ if (lean_is_scalar(f)) { lean_dec(a1); lean_dec(a2); lean_dec(a3); lean_dec(a4);
 unsigned arity = lean_closure_arity(f);
 unsigned fixed = lean_closure_num_fixed(f);
 if (arity == fixed + 11) {
-  if (is_exclusive(f)) {
+  if (lean_is_exclusive(f)) {
     switch (arity) {
     case 11: { obj* r = FN11(f)(a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11); lean_free_small_object(f); return r; }
     case 12: { obj* r = FN12(f)(fx(0), a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11); lean_free_small_object(f); return r; }
@@ -692,7 +692,7 @@ if (lean_is_scalar(f)) { lean_dec(a1); lean_dec(a2); lean_dec(a3); lean_dec(a4);
 unsigned arity = lean_closure_arity(f);
 unsigned fixed = lean_closure_num_fixed(f);
 if (arity == fixed + 12) {
-  if (is_exclusive(f)) {
+  if (lean_is_exclusive(f)) {
     switch (arity) {
     case 12: { obj* r = FN12(f)(a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12); lean_free_small_object(f); return r; }
     case 13: { obj* r = FN13(f)(fx(0), a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12); lean_free_small_object(f); return r; }
@@ -734,7 +734,7 @@ if (lean_is_scalar(f)) { lean_dec(a1); lean_dec(a2); lean_dec(a3); lean_dec(a4);
 unsigned arity = lean_closure_arity(f);
 unsigned fixed = lean_closure_num_fixed(f);
 if (arity == fixed + 13) {
-  if (is_exclusive(f)) {
+  if (lean_is_exclusive(f)) {
     switch (arity) {
     case 13: { obj* r = FN13(f)(a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12, a13); lean_free_small_object(f); return r; }
     case 14: { obj* r = FN14(f)(fx(0), a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12, a13); lean_free_small_object(f); return r; }
@@ -774,7 +774,7 @@ if (lean_is_scalar(f)) { lean_dec(a1); lean_dec(a2); lean_dec(a3); lean_dec(a4);
 unsigned arity = lean_closure_arity(f);
 unsigned fixed = lean_closure_num_fixed(f);
 if (arity == fixed + 14) {
-  if (is_exclusive(f)) {
+  if (lean_is_exclusive(f)) {
     switch (arity) {
     case 14: { obj* r = FN14(f)(a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12, a13, a14); lean_free_small_object(f); return r; }
     case 15: { obj* r = FN15(f)(fx(0), a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12, a13, a14); lean_free_small_object(f); return r; }
@@ -812,7 +812,7 @@ if (lean_is_scalar(f)) { lean_dec(a1); lean_dec(a2); lean_dec(a3); lean_dec(a4);
 unsigned arity = lean_closure_arity(f);
 unsigned fixed = lean_closure_num_fixed(f);
 if (arity == fixed + 15) {
-  if (is_exclusive(f)) {
+  if (lean_is_exclusive(f)) {
     switch (arity) {
     case 15: { obj* r = FN15(f)(a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12, a13, a14, a15); lean_free_small_object(f); return r; }
     case 16: { obj* r = FN16(f)(fx(0), a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12, a13, a14, a15); lean_free_small_object(f); return r; }
@@ -848,7 +848,7 @@ if (lean_is_scalar(f)) { lean_dec(a1); lean_dec(a2); lean_dec(a3); lean_dec(a4);
 unsigned arity = lean_closure_arity(f);
 unsigned fixed = lean_closure_num_fixed(f);
 if (arity == fixed + 16) {
-  if (is_exclusive(f)) {
+  if (lean_is_exclusive(f)) {
     switch (arity) {
     case 16: { obj* r = FN16(f)(a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12, a13, a14, a15, a16); lean_free_small_object(f); return r; }
     }