investigate bts 20881

examples/bts/20881.why

+
+
+theory OK
+
+type t 'a = A | B (t 'a)
+
+
+goal g : forall x: t 'a. A <> B x
+
+end
+
+
+theory Bug1
+
+type t 'a = A int
+
+function f (t 'a) : 'a
+
+goal g : let p = (A 0: t int) in
+         let q = (A 1: t int) in
+         f p = f q
+
+end
+
 theory Bug
     use import map.Map