New bug exposed.

diff --git a/helm/matita/tests/elim.ma b/helm/matita/tests/elim.ma
index fcc130e9ecece535348456f59a0abe07b4ba549d..7c4031971307cd524eeca3379431c823ad7d2e1f 100644 (file)
--- a/helm/matita/tests/elim.ma
+++ b/helm/matita/tests/elim.ma
@@ -53,3 +53,27 @@ qed.
 theorem foo: let ax \def refl_equal ? 0 in t ax = t ax.
  elim t; reflexivity.
 qed.
+
+(* This test shows a bug where elim opens a new unus{ed,eful} goal *)
+
+alias symbol "eq" (instance 0) = "Coq's leibnitz's equality".
+alias id "O" = "cic:/Coq/Init/Datatypes/nat.ind#xpointer(1/1/1)".
+
+inductive sum (n:nat) : nat \to nat \to Set \def
+  k: \forall x,y. n = x + y \to sum n x y.
+  
+theorem t: \forall x,y. \forall H: sum x y O.
+          match H with [ (k a b p) \Rightarrow a ] = x.
+ intros.
+ cut (y = y \to O = O \to match H with [ (k a b p) \Rightarrow a] = x).
+ apply Hcut; reflexivity.
+ apply
+  (sum_ind ?
+    (\lambda a,b,K. y=a \to O=b \to
+        match K with [ (k a b p) \Rightarrow a ] = x)
+     ? ? ? H).
+ simplify. intros.
+ generalize in match H1.
+ rewrite < H2; rewrite < H3.intro.
+ rewrite > H4.auto.
+qed.