diff --git a/src/frontends/lean/builtin_cmds.cpp b/src/frontends/lean/builtin_cmds.cpp
index 65f586bf67..e35008e17d 100644
--- a/src/frontends/lean/builtin_cmds.cpp
+++ b/src/frontends/lean/builtin_cmds.cpp
@@ -551,7 +551,8 @@ static environment run_command_cmd(parser & p) {
     tactic               = mk_app(mk_constant(get_has_bind_and_then_name()), tactic, try_triv);
     expr val             = mk_typed_expr(mk_true(), mk_by(tactic));
     bool check_unassigned = false;
-    elaborate(env, opts, "_run_command", mctx, local_context(), val, check_unassigned);
+    bool recover_from_errors = true;
+    elaborate(env, opts, "_run_command", mctx, local_context(), val, check_unassigned, recover_from_errors);
     return env;
 }
 
diff --git a/src/frontends/lean/elaborator.cpp b/src/frontends/lean/elaborator.cpp
index 3da35e9984..e7f623dab7 100644
--- a/src/frontends/lean/elaborator.cpp
+++ b/src/frontends/lean/elaborator.cpp
@@ -3660,8 +3660,7 @@ expr elaborator::finalize_theorem_proof(expr const & val, theorem_finalization_i
 pair<expr, level_param_names>
 elaborate(environment & env, options const & opts, name const & decl_name,
           metavar_context & mctx, local_context const & lctx, expr const & e,
-          bool check_unassigned) {
-    bool recover_from_errors = false;
+          bool check_unassigned, bool recover_from_errors) {
     elaborator elab(env, opts, decl_name, mctx, lctx, recover_from_errors);
     expr r = elab.elaborate(e);
     auto p = elab.finalize(r, check_unassigned, true);
diff --git a/src/frontends/lean/elaborator.h b/src/frontends/lean/elaborator.h
index 799a8e0ac3..d172c6e2ce 100644
--- a/src/frontends/lean/elaborator.h
+++ b/src/frontends/lean/elaborator.h
@@ -335,7 +335,7 @@ public:
 
 pair<expr, level_param_names> elaborate(environment & env, options const & opts, name const & decl_name,
                                         metavar_context & mctx, local_context const & lctx,
-                                        expr const & e, bool check_unassigend);
+                                        expr const & e, bool check_unassigned, bool recover_from_errors);
 
 /** \brief Translated local constants (and undefined constants) occurring in \c e into
     local constants provided by \c ctx.
diff --git a/src/frontends/lean/parser.cpp b/src/frontends/lean/parser.cpp
index 32491eae08..dac62b8035 100644
--- a/src/frontends/lean/parser.cpp
+++ b/src/frontends/lean/parser.cpp
@@ -753,7 +753,7 @@ pair<expr, level_param_names> parser::elaborate(name const & decl_name,
                                                 expr const & e, bool check_unassigned) {
     expr tmp_e  = adapter.translate_to(e);
     pair<expr, level_param_names> r =
-        ::lean::elaborate(m_env, get_options(), decl_name, mctx, adapter.lctx(), tmp_e, check_unassigned);
+        ::lean::elaborate(m_env, get_options(), decl_name, mctx, adapter.lctx(), tmp_e, check_unassigned, m_error_recovery);
     expr new_e = r.first;
     new_e      = adapter.translate_from(new_e);
     return mk_pair(new_e, r.second);
diff --git a/tests/lean/1279.lean.expected.out b/tests/lean/1279.lean.expected.out
index 96706aa67a..0095aadb4e 100644
--- a/tests/lean/1279.lean.expected.out
+++ b/tests/lean/1279.lean.expected.out
@@ -6,3 +6,20 @@ has type
   source.Hom A B
 but is expected to have type
   source.Hom C ?m_1
+1279.lean:12:55: error: type mismatch at application
+  target.compose (onMorphisms g) (onMorphisms f)
+term
+  onMorphisms f
+has type
+  target.Hom (onObjects A) (onObjects B)
+but is expected to have type
+  target.Hom (onObjects C) (onObjects ?m_1)
+1279.lean:12:33: error: don't know how to synthesize placeholder
+context:
+source target : Category,
+onObjects : source.Obj → target.Obj,
+onMorphisms : Π ⦃A B : source.Obj⦄, source.Hom A B → target.Hom (onObjects A) (onObjects B),
+A B C : source.Obj,
+f : source.Hom A B,
+g : source.Hom B C
+⊢ source.Obj
diff --git a/tests/lean/choice_expl.lean.expected.out b/tests/lean/choice_expl.lean.expected.out
index 362aab759a..17287b6b37 100644
--- a/tests/lean/choice_expl.lean.expected.out
+++ b/tests/lean/choice_expl.lean.expected.out
@@ -5,3 +5,4 @@ choice_expl.lean:15:7: error: ambiguous overload, possible interpretations
   N1.pr a b
 Additional information:
 choice_expl.lean:15:7: context: switched to basic overload resolution where arguments are elaborated without any information about the expected type because expected type was not available
+⁇ : ?M_1
diff --git a/tests/lean/coe1.lean.expected.out b/tests/lean/coe1.lean.expected.out
index bc5249e4c7..5f5f73e08c 100644
--- a/tests/lean/coe1.lean.expected.out
+++ b/tests/lean/coe1.lean.expected.out
@@ -11,6 +11,7 @@ has type
   real
 but is expected to have type
   int
+⁇ : ?M_1
 ↑i + x : real
 x + ↑n : real
 coe1.lean:35:9: error: type mismatch at application
@@ -21,6 +22,7 @@ has type
   real
 but is expected to have type
   ℕ
+⁇ : ?M_1
 ↑n + x : real
 ↑i + x : real
 ↑n + x : real
diff --git a/tests/lean/coe2.lean.expected.out b/tests/lean/coe2.lean.expected.out
index af71e818b8..170a72da12 100644
--- a/tests/lean/coe2.lean.expected.out
+++ b/tests/lean/coe2.lean.expected.out
@@ -11,6 +11,7 @@ has type
   real
 but is expected to have type
   int
+⁇ : ?M_1
 i + x : real
 x + n : real
 coe2.lean:37:9: error: type mismatch at application
@@ -21,4 +22,5 @@ has type
   real
 but is expected to have type
   ℕ
+⁇ : ?M_1
 n + x : real
diff --git a/tests/lean/def4.lean.expected.out b/tests/lean/def4.lean.expected.out
index d246e3e7a4..a769333a58 100644
--- a/tests/lean/def4.lean.expected.out
+++ b/tests/lean/def4.lean.expected.out
@@ -7,6 +7,7 @@ has type
   ℕ
 but is expected to have type
   A
+⁇ : ?M_1
 g : A → A
 def4.lean:17:9: error: type mismatch at application
   g 0
@@ -16,6 +17,7 @@ has type
   ℕ
 but is expected to have type
   A
+⁇ : ?M_1
 f : Π (A : Type u_1), A → A
 f ℕ 0 : ℕ
 g 0 : ℕ
diff --git a/tests/lean/elab1.lean.expected.out b/tests/lean/elab1.lean.expected.out
index ec6956041f..f73bb86c5e 100644
--- a/tests/lean/elab1.lean.expected.out
+++ b/tests/lean/elab1.lean.expected.out
@@ -3,4 +3,6 @@
 elab1.lean:13:7: error: invalid '@', function is overloaded, use fully qualified names (overloads: boo.subst, foo.subst)
 elab1.lean:15:7: error: invalid '@@', function is overloaded, use fully qualified names (overloads: boo.subst, foo.subst)
 elab1.lean:19:7: error: invalid overloaded application, elaborator has special support for 'eq.subst' (it is handled as an "eliminator"), but this kind of constant cannot be overloaded (solution: use fully qualified names) (overloads: eq.subst, boo.subst, foo.subst)
+⁇ : ?M_1
 elab1.lean:25:7: error: invalid 'eq.subst' application, elaborator has special support for this kind of application (it is handled as an "eliminator"), but the expected type must be known
+⁇ : ?M_1
diff --git a/tests/lean/elab11.lean.expected.out b/tests/lean/elab11.lean.expected.out
index 5a8de89f82..3ab20d59ae 100644
--- a/tests/lean/elab11.lean.expected.out
+++ b/tests/lean/elab11.lean.expected.out
@@ -3,6 +3,7 @@ elab11.lean:6:7: error: ambiguous overload, possible interpretations
   boo.f 1
 Additional information:
 elab11.lean:6:7: context: switched to basic overload resolution where arguments are elaborated without any information about the expected type because expected type was not available
+⁇ : ?M_1
 bla.f 1 : ℕ
 boo.f 1 : bool
 elab11.lean:16:8: error: none of the overloads are applicable
@@ -41,3 +42,4 @@ has type
   bool
 but is expected to have type
   string
+⁇ : string
diff --git a/tests/lean/elab12.lean.expected.out b/tests/lean/elab12.lean.expected.out
index 1989ab672e..9f4632c385 100644
--- a/tests/lean/elab12.lean.expected.out
+++ b/tests/lean/elab12.lean.expected.out
@@ -1,16 +1,31 @@
 elab12.lean:1:31: error: type expected at
   0
+elab12.lean:1:39: error: function expected at
+  rfl
+Additional information:
+elab12.lean:1:39: context: switched to simple application elaboration procedure because failed to use expected type to elaborate it, error message
+  too many arguments
+elab12.lean:2:2: error: function expected at
+  H
+λ (a : ℕ), have H : ⁇, from ⁇, ⁇ : ∀ (a : ℕ), a = a
 elab12.lean:4:43: error: function expected at
   rfl
 Additional information:
 elab12.lean:4:43: context: switched to simple application elaboration procedure because failed to use expected type to elaborate it, error message
   too many arguments
+elab12.lean:5:2: error: function expected at
+  H
+λ (a : ℕ), have H : a = a, from ⁇, ⁇ : ∀ (a : ℕ), a = a
 elab12.lean:7:45: error: invalid have-expression, expression
   a + 0
 has type
   ℕ
 but is expected to have type
   a = a
+elab12.lean:8:2: error: function expected at
+  H
+λ (a : ℕ), have H : a = a, from ⁇, ⁇ : ∀ (a : ℕ), a = a
 elab12.lean:11:2: error: function expected at
   H
+λ (a : ℕ), have H : a = a, from rfl, ⁇ : ∀ (a : ℕ), a = a
 λ (a : ℕ), have H : a = a, from rfl, H : ∀ (a : ℕ), a = a
diff --git a/tests/lean/elab2.lean.expected.out b/tests/lean/elab2.lean.expected.out
index 22431f4f8d..24dd5c2238 100644
--- a/tests/lean/elab2.lean.expected.out
+++ b/tests/lean/elab2.lean.expected.out
@@ -7,4 +7,5 @@ has type
   bool
 but is expected to have type
   nat
+⁇ : ?M_1
 @bla.{0 0} nat bool (@has_zero.zero.{0} nat nat.has_zero) (@has_zero.zero.{0} nat nat.has_zero) bool.tt : nat
diff --git a/tests/lean/elab4.lean.expected.out b/tests/lean/elab4.lean.expected.out
index 799236aa58..fd170b06f5 100644
--- a/tests/lean/elab4.lean.expected.out
+++ b/tests/lean/elab4.lean.expected.out
@@ -13,11 +13,13 @@ function expected at
   boo.f 0 1 2
 Additional information:
 elab4.lean:13:7: context: switched to basic overload resolution where arguments are elaborated without any information about the expected type because expected type was not available
+⁇ : ?M_1
 elab4.lean:15:7: error: ambiguous overload, possible interpretations
   foo.f 0 1
   boo.f 0 1
 Additional information:
 elab4.lean:15:7: context: switched to basic overload resolution where arguments are elaborated without any information about the expected type because expected type was not available
+⁇ : ?M_1
 foo.f bool.tt 2 : bool
 bla.f bool.tt bool.ff bool.tt : bool → bool
 elab4.lean:21:7: error: ambiguous overload, possible interpretations
@@ -25,4 +27,5 @@ elab4.lean:21:7: error: ambiguous overload, possible interpretations
   foo.f bool.tt bool.ff
 Additional information:
 elab4.lean:21:7: context: switched to basic overload resolution where arguments are elaborated without any information about the expected type because expected type was not available
+⁇ : ?M_1
 foo.f 0 1 : ℕ
diff --git a/tests/lean/elab4b.lean.expected.out b/tests/lean/elab4b.lean.expected.out
index db239203d8..bf058ac9d1 100644
--- a/tests/lean/elab4b.lean.expected.out
+++ b/tests/lean/elab4b.lean.expected.out
@@ -12,13 +12,16 @@ function expected at
   f 0 1 2
 Additional information:
 elab4b.lean:9:7: context: switched to basic overload resolution where arguments are elaborated without any information about the expected type because expected type was not available
+⁇ : ?M_1
 elab4b.lean:11:7: error: ambiguous overload, possible interpretations
   foo.f 0 1
   boo.f 0 1
 Additional information:
 elab4b.lean:11:7: context: switched to basic overload resolution where arguments are elaborated without any information about the expected type because expected type was not available
+⁇ : ?M_1
 elab4b.lean:13:7: error: ambiguous overload, possible interpretations
   bla.f bool.tt bool.ff
   foo.f bool.tt bool.ff
 Additional information:
 elab4b.lean:13:7: context: switched to basic overload resolution where arguments are elaborated without any information about the expected type because expected type was not available
+⁇ : ?M_1
diff --git a/tests/lean/elab_error_recovery.lean.expected.out b/tests/lean/elab_error_recovery.lean.expected.out
index fe429101d1..f683b46b75 100644
--- a/tests/lean/elab_error_recovery.lean.expected.out
+++ b/tests/lean/elab_error_recovery.lean.expected.out
@@ -39,3 +39,4 @@ nat.succ (nat.succ (nat.succ (nat.succ ⁇)))
 2
 elab_error_recovery.lean:21:13: error: type expected at
   0
+∀ (x : ⁇), x = x : Prop
diff --git a/tests/lean/error_full_names.lean.expected.out b/tests/lean/error_full_names.lean.expected.out
index fc25342e8d..9391b49120 100644
--- a/tests/lean/error_full_names.lean.expected.out
+++ b/tests/lean/error_full_names.lean.expected.out
@@ -1,5 +1,8 @@
 error_full_names.lean:4:7: error: failed to synthesize type class instance for
 ⊢ has_zero nat
+error_full_names.lean:4:9: error: failed to synthesize type class instance for
+⊢ has_add nat
+0 + nat.zero : nat
 error_full_names.lean:8:7: error: type mismatch at application
   nat.succ nat.zero
 term
@@ -8,3 +11,4 @@ has type
   nat
 but is expected to have type
   ℕ
+⁇ : ?M_1
diff --git a/tests/lean/error_pos.lean.expected.out b/tests/lean/error_pos.lean.expected.out
index 73a9f90ce1..60f74b46fa 100644
--- a/tests/lean/error_pos.lean.expected.out
+++ b/tests/lean/error_pos.lean.expected.out
@@ -5,10 +5,13 @@ error_pos.lean:4:43: error: type expected at
   B
 error_pos.lean:9:40: error: type expected at
   B
+λ (A : Type) (B : A → Type) (b : ⁇), true : Π (A : Type), (A → Type) → ⁇ → Prop
 error_pos.lean:11:36: error: type expected at
   B
+λ (A : Type) (B : A → Type), ⁇ → true : Π (A : Type), (A → Type) → Prop
 error_pos.lean:13:43: error: type expected at
   B
+λ (A : Type) (B : A → Type) (b : ⁇), b : Π (A : Type), (A → Type) → ⁇ → ⁇
 error_pos.lean:15:105: error: invalid let-expression, expression
   a₁
 has type
diff --git a/tests/lean/field_access.lean.expected.out b/tests/lean/field_access.lean.expected.out
index 9320ce4078..22c33e4c8d 100644
--- a/tests/lean/field_access.lean.expected.out
+++ b/tests/lean/field_access.lean.expected.out
@@ -3,10 +3,12 @@ field_access.lean:5:8: error: invalid projection, structure expected
   l
 has type
   list ℕ
+⁇ : ?M_1
 field_access.lean:7:13: error: invalid projection, structure has only 2 field(s)
   (1, 2)
 which has type
   ?m_1 × ?m_2
+⁇ : ?M_1
 field_access.lean:10:1: error: invalid field notation, 'forr' is not a valid "field" because environment does not contain 'list.forr'
   l
 which has type
diff --git a/tests/lean/inst_error.lean.expected.out b/tests/lean/inst_error.lean.expected.out
index 8912b26026..580577defb 100644
--- a/tests/lean/inst_error.lean.expected.out
+++ b/tests/lean/inst_error.lean.expected.out
@@ -2,3 +2,4 @@ inst_error.lean:1:39: error: failed to synthesize type class instance for
 A : Type,
 a b c : A
 ⊢ decidable (a = b ∧ a = c)
+λ (A : Type) (a b c : A), ite (a = b ∧ a = c) tt ff : Π (A : Type), A → A → A → bool
diff --git a/tests/lean/instance_cache_bug1.lean.expected.out b/tests/lean/instance_cache_bug1.lean.expected.out
index fe99bce2f2..4ee1207edc 100644
--- a/tests/lean/instance_cache_bug1.lean.expected.out
+++ b/tests/lean/instance_cache_bug1.lean.expected.out
@@ -1,3 +1,4 @@
 instance_cache_bug1.lean:5:9: error: failed to synthesize type class instance for
 ⊢ has_add A
 a + a : A
+a + a : A
diff --git a/tests/lean/interactive/info_id_pre_elab.lean.expected.out b/tests/lean/interactive/info_id_pre_elab.lean.expected.out
index 6bff823109..fbeb8fc46c 100644
--- a/tests/lean/interactive/info_id_pre_elab.lean.expected.out
+++ b/tests/lean/interactive/info_id_pre_elab.lean.expected.out
@@ -1,7 +1,8 @@
 {"msgs":[{"caption":"","file_name":"f","pos_col":0,"pos_line":6,"severity":"error","text":"invalid expression, `)` expected"}],"response":"all_messages"}
 {"msgs":[{"caption":"","file_name":"f","pos_col":0,"pos_line":6,"severity":"error","text":"invalid expression, `)` expected"},{"caption":"","file_name":"f","pos_col":8,"pos_line":3,"severity":"error","text":"ambiguous overload, possible interpretations\n  trace\n  tactic.trace\nAdditional information:\nf:3:8: context: switched to basic overload resolution where arguments are elaborated without any information about the expected type because expected type was not available"}],"response":"all_messages"}
-{"msgs":[{"caption":"","file_name":"f","pos_col":0,"pos_line":6,"severity":"error","text":"invalid expression, `)` expected"},{"caption":"","file_name":"f","pos_col":8,"pos_line":3,"severity":"error","text":"ambiguous overload, possible interpretations\n  trace\n  tactic.trace\nAdditional information:\nf:3:8: context: switched to basic overload resolution where arguments are elaborated without any information about the expected type because expected type was not available"},{"caption":"","file_name":"f","pos_col":27,"pos_line":7,"severity":"error","text":"invalid expression, `)` expected"}],"response":"all_messages"}
-{"msgs":[{"caption":"","file_name":"f","pos_col":0,"pos_line":6,"severity":"error","text":"invalid expression, `)` expected"},{"caption":"","file_name":"f","pos_col":8,"pos_line":3,"severity":"error","text":"ambiguous overload, possible interpretations\n  trace\n  tactic.trace\nAdditional information:\nf:3:8: context: switched to basic overload resolution where arguments are elaborated without any information about the expected type because expected type was not available"},{"caption":"","file_name":"f","pos_col":27,"pos_line":7,"severity":"error","text":"invalid expression, `)` expected"},{"caption":"check result","file_name":"f","pos_col":0,"pos_line":6,"severity":"information","text":"λ (tac : tactic unit), (abstract tac none) : tactic unit → tactic unit"}],"response":"all_messages"}
+{"msgs":[{"caption":"","file_name":"f","pos_col":0,"pos_line":6,"severity":"error","text":"invalid expression, `)` expected"},{"caption":"","file_name":"f","pos_col":8,"pos_line":3,"severity":"error","text":"ambiguous overload, possible interpretations\n  trace\n  tactic.trace\nAdditional information:\nf:3:8: context: switched to basic overload resolution where arguments are elaborated without any information about the expected type because expected type was not available"},{"caption":"check result","file_name":"f","pos_col":0,"pos_line":3,"severity":"information","text":"⁇ : ?M_1"}],"response":"all_messages"}
+{"msgs":[{"caption":"","file_name":"f","pos_col":0,"pos_line":6,"severity":"error","text":"invalid expression, `)` expected"},{"caption":"","file_name":"f","pos_col":8,"pos_line":3,"severity":"error","text":"ambiguous overload, possible interpretations\n  trace\n  tactic.trace\nAdditional information:\nf:3:8: context: switched to basic overload resolution where arguments are elaborated without any information about the expected type because expected type was not available"},{"caption":"check result","file_name":"f","pos_col":0,"pos_line":3,"severity":"information","text":"⁇ : ?M_1"},{"caption":"","file_name":"f","pos_col":27,"pos_line":7,"severity":"error","text":"invalid expression, `)` expected"}],"response":"all_messages"}
+{"msgs":[{"caption":"","file_name":"f","pos_col":0,"pos_line":6,"severity":"error","text":"invalid expression, `)` expected"},{"caption":"","file_name":"f","pos_col":8,"pos_line":3,"severity":"error","text":"ambiguous overload, possible interpretations\n  trace\n  tactic.trace\nAdditional information:\nf:3:8: context: switched to basic overload resolution where arguments are elaborated without any information about the expected type because expected type was not available"},{"caption":"check result","file_name":"f","pos_col":0,"pos_line":3,"severity":"information","text":"⁇ : ?M_1"},{"caption":"","file_name":"f","pos_col":27,"pos_line":7,"severity":"error","text":"invalid expression, `)` expected"},{"caption":"check result","file_name":"f","pos_col":0,"pos_line":6,"severity":"information","text":"λ (tac : tactic unit), (abstract tac none) : tactic unit → tactic unit"}],"response":"all_messages"}
 {"message":"file invalidated","response":"ok","seq_num":0}
 {"response":"ok","seq_num":4}
 {"record":{"full-id":"tactic.abstract","source":,"type":"tactic unit → opt_param (option name) none → opt_param bool tt → tactic unit"},"response":"ok","seq_num":7}
diff --git a/tests/lean/let1.lean.expected.out b/tests/lean/let1.lean.expected.out
index 94a862d745..46ff213041 100644
--- a/tests/lean/let1.lean.expected.out
+++ b/tests/lean/let1.lean.expected.out
@@ -12,3 +12,10 @@ has type
   Π (p q : bool), p → q → Π (c : bool), (p → q → c) → c
 but is expected to have type
   Π (p q : bool), p → q → and q p
+let bool : Type := Prop,
+    and : bool → bool → Prop := λ (p q : bool), Π (c : bool), (p → q → c) → c,
+    and_intro : Π (p q : bool), p → q → and q p := ⁇,
+    and_elim_left : Π (p q : bool), and p q → p := λ (p q : bool) (H : and p q), H p (λ (H1 : p) (H2 : q), H1),
+    and_elim_right : Π (p q : bool), and p q → q := λ (p q : bool) (H : and p q), H q (λ (H1 : p) (H2 : q), H2)
+in and_intro :
+  ∀ (p q : Prop), p → q → (λ (p q : Prop), ∀ (c : Prop), (p → q → c) → c) q p
diff --git a/tests/lean/mismatch.lean.expected.out b/tests/lean/mismatch.lean.expected.out
index a703d5c055..4109513b6e 100644
--- a/tests/lean/mismatch.lean.expected.out
+++ b/tests/lean/mismatch.lean.expected.out
@@ -6,3 +6,4 @@ has type
   num
 but is expected to have type
   ℕ
+⁇ : ?M_1
diff --git a/tests/lean/nary_overload.lean.expected.out b/tests/lean/nary_overload.lean.expected.out
index 4b93f917fa..b2109a88e9 100644
--- a/tests/lean/nary_overload.lean.expected.out
+++ b/tests/lean/nary_overload.lean.expected.out
@@ -3,6 +3,7 @@ nary_overload.lean:16:7: error: ambiguous overload, possible interpretations
   [a, b, c]
 Additional information:
 nary_overload.lean:16:7: context: switched to basic overload resolution where arguments are elaborated without any information about the expected type because expected type was not available
+⁇ : ?M_1
 [a, b, c] : vec A
 [a, b, c] : lst A
 @vec.cons A a (@vec.cons A b (@vec.cons A c (@vec.nil A))) : vec.{0} A
diff --git a/tests/lean/no_coe.lean.expected.out b/tests/lean/no_coe.lean.expected.out
index bd6ffb145d..9f2369cd71 100644
--- a/tests/lean/no_coe.lean.expected.out
+++ b/tests/lean/no_coe.lean.expected.out
@@ -7,3 +7,4 @@ has type
   bool
 but is expected to have type
   Prop
+⁇ : ?M_1
diff --git a/tests/lean/notation_error_pos.lean.expected.out b/tests/lean/notation_error_pos.lean.expected.out
index c3b8747ac7..899a1e590f 100644
--- a/tests/lean/notation_error_pos.lean.expected.out
+++ b/tests/lean/notation_error_pos.lean.expected.out
@@ -1,9 +1,19 @@
 notation_error_pos.lean:6:7: error: failed to synthesize type class instance for
 ⊢ has_one string
+notation_error_pos.lean:6:7: error: failed to synthesize type class instance for
+⊢ has_add string
+"a" + 1 : string
 notation_error_pos.lean:8:7: error: failed to synthesize type class instance for
 ⊢ has_one string
+notation_error_pos.lean:8:7: error: failed to synthesize type class instance for
+⊢ has_add string
+"a" + 1 : string
 notation_error_pos.lean:10:7: error: failed to synthesize type class instance for
 ⊢ has_one string
+notation_error_pos.lean:10:7: error: failed to synthesize type class instance for
+⊢ has_add string
+1 + "a" : string
 notation_error_pos.lean:12:7: error: failed to synthesize type class instance for
 x : string
 ⊢ has_add string
+λ (x : string), x + "b" : string → string
diff --git a/tests/lean/num2.lean.expected.out b/tests/lean/num2.lean.expected.out
index 9adf3b4a0d..5b904ef1bb 100644
--- a/tests/lean/num2.lean.expected.out
+++ b/tests/lean/num2.lean.expected.out
@@ -1,5 +1,11 @@
 o : N
 z : N
 eq a gz : Prop
+num2.lean:24:8: error: failed to synthesize type class instance for
+⊢ has_zero G
+num2.lean:24:8: error: invalid type ascription, expression has type
+  N
+but is expected to have type
+  G
 eq gz a : Prop
 eq b z : Prop
diff --git a/tests/lean/num3.lean.expected.out b/tests/lean/num3.lean.expected.out
index 3c1ba29c9e..123d76c69c 100644
--- a/tests/lean/num3.lean.expected.out
+++ b/tests/lean/num3.lean.expected.out
@@ -1,3 +1,7 @@
 @eq N a z : Prop
+num3.lean:14:12: error: invalid type ascription, expression has type
+  N
+but is expected to have type
+  num
 @eq num 2 1 : Prop
 @eq num 2 1 : Prop
diff --git a/tests/lean/over_notation.lean.expected.out b/tests/lean/over_notation.lean.expected.out
index 3838b1e0fc..91bc42d1bf 100644
--- a/tests/lean/over_notation.lean.expected.out
+++ b/tests/lean/over_notation.lean.expected.out
@@ -22,5 +22,6 @@ but is expected to have type
   nat
 Additional information:
 over_notation.lean:11:10: context: switched to basic overload resolution where arguments are elaborated without any information about the expected type because expected type was not available
+⁇ : ?M_1
 f 1 (f 2 (f 3 0)) : nat
 g "a" (g "b" (g "c" "")) : string
diff --git a/tests/lean/private_structure.lean.expected.out b/tests/lean/private_structure.lean.expected.out
index cada7bdeb0..5e335b5c79 100644
--- a/tests/lean/private_structure.lean.expected.out
+++ b/tests/lean/private_structure.lean.expected.out
@@ -26,4 +26,5 @@ private_structure.lean:30:7: error: unknown identifier 'point.y'
 def foo.bla : Type :=
 point
 private_structure.lean:35:8: error: invalid constructor ⟨...⟩, type is a private inductive datatype
+⁇ : foo.bla
 foo.mk : foo.bla
diff --git a/tests/lean/proj_notation.lean.expected.out b/tests/lean/proj_notation.lean.expected.out
index 8f1bd91311..d399b76ff6 100644
--- a/tests/lean/proj_notation.lean.expected.out
+++ b/tests/lean/proj_notation.lean.expected.out
@@ -9,15 +9,18 @@ proj_notation.lean:29:19: error: invalid field notation, 'fst' is not a valid "f
   c
 which has type
   car
+λ (c : car), ⁇ : car → ?M_1
 proj_notation.lean:31:21: error: invalid projection, index must be greater than 0
 proj_notation.lean:33:19: error: invalid projection, structure has only 2 field(s)
   c
 which has type
   car
+λ (c : car), ⁇ : car → ?M_1
 proj_notation.lean:35:19: error: invalid projection, structure expected
   n
 has type
   ℕ
+λ (n : ℕ), ⁇ : ℕ → ?M_1
 p.fst : ℕ
 p.snd : ℕ
 λ (c : car), (c.pos).y : car → ℕ
diff --git a/tests/lean/slow_error.lean.expected.out b/tests/lean/slow_error.lean.expected.out
index 6bcd5537ba..3614524f13 100644
--- a/tests/lean/slow_error.lean.expected.out
+++ b/tests/lean/slow_error.lean.expected.out
@@ -6,3 +6,4 @@ has type
   string
 but is expected to have type
   caching_user_attribute string
+⁇ : ?M_1
diff --git a/tests/lean/t10.lean.expected.out b/tests/lean/t10.lean.expected.out
index cfbb81a723..3243bb7732 100644
--- a/tests/lean/t10.lean.expected.out
+++ b/tests/lean/t10.lean.expected.out
@@ -7,6 +7,7 @@ has type
   B
 but is expected to have type
   N
+⁇ : ?M_1
 [x, y, z, x, y, y] : list
 [x] : list
 [] : list
diff --git a/tests/lean/t12.lean.expected.out b/tests/lean/t12.lean.expected.out
index 5f59b38a1f..3fd8c0df5e 100644
--- a/tests/lean/t12.lean.expected.out
+++ b/tests/lean/t12.lean.expected.out
@@ -1,3 +1,5 @@
 λ (f g : N → N → N) (x y : N), f x (g x y) : (N → N → N) → (N → N → N) → N → N → N
 t12.lean:7:7: error: function expected at
   a
+⁇ : ?M_1
+t12.lean:7:8: error: command expected