Fix bug #4420: check_types was losing universe constraints.

1 files changed, 19 insertions, 0 deletions

diff --git a/test-suite/bugs/closed/4420.v b/test-suite/bugs/closed/4420.v
new file mode 100644
index 0000000000..0e16cb2399
--- /dev/null
+++ b/test-suite/bugs/closed/4420.v
@@ -0,0 +1,19 @@
+Module foo.
+  Context (Char : Type).
+  Axiom foo : Type -> Type.
+  Goal foo Char = foo Char.
+    change foo with (fun x => foo x).
+    cbv beta.
+    reflexivity.
+  Defined. 
+End foo.
+
+Inductive foo (A : Type) : Prop := I. (*Top.1*)
+Lemma bar : foo Type. (*Top.3*)
+Proof.
+  Set Printing Universes.
+change foo with (fun x : Type => foo x). (*Top.4*)
+cbv beta.
+apply I. (* I Type@{Top.3} : (fun x : Type@{Top.4} => foo x) Type@{Top.3} *)
+Defined.
+