Fix bug #2456 and wrong unfolding of lets in the goal due to [unfold] doing zeta reductions.

git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@14564 85f007b7-540e-0410-9357-904b9bb8a0f7

1 files changed, 53 insertions, 0 deletions

diff --git a/test-suite/bugs/closed/shouldsucceed/2456.v b/test-suite/bugs/closed/shouldsucceed/2456.v
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index 000000000..56f046c4d
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+++ b/test-suite/bugs/closed/shouldsucceed/2456.v
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+
+Require Import Equality.
+
+Parameter Patch : nat -> nat -> Set.
+
+Inductive Catch (from to : nat) : Type
+    := MkCatch : forall (p : Patch from to),
+                 Catch from to.
+Implicit Arguments MkCatch [from to].
+
+Inductive CatchCommute5
+        : forall {from mid1 mid2 to : nat},
+          Catch from mid1
+       -> Catch mid1 to
+       -> Catch from mid2
+       -> Catch mid2 to
+       -> Prop
+     := MkCatchCommute5 :
+           forall {from mid1 mid2 to : nat}
+                  (p : Patch from mid1)
+                  (q : Patch mid1 to)
+                  (q' : Patch from mid2)
+                  (p' : Patch mid2 to),
+           CatchCommute5 (MkCatch p) (MkCatch q) (MkCatch q') (MkCatch p').
+
+Inductive CatchCommute {from mid1 mid2 to : nat}
+                       (p : Catch from mid1)
+                       (q : Catch mid1 to)
+                       (q' : Catch from mid2)
+                       (p' : Catch mid2 to)
+                     : Prop
+    := isCatchCommute5 : forall (catchCommuteDetails : CatchCommute5 p q q' p'),
+                         CatchCommute p q q' p'.
+Notation "<< p , q >> <~> << q' , p' >>"
+    := (CatchCommute p q q' p')
+    (at level 60, no associativity).
+
+Lemma CatchCommuteUnique2 :
+      forall {from mid mid' to : nat}
+             {p   : Catch from mid}  {q   : Catch mid  to}
+             {q'  : Catch from mid'} {p'  : Catch mid' to}
+             {q'' : Catch from mid'} {p'' : Catch mid' to}
+             (commute1 : <<p, q>> <~> <<q', p'>>)
+             (commute2 : <<p, q>> <~> <<q'', p''>>),
+      (p' = p'') /\ (q' = q'').
+Proof with auto.
+intros.
+set (X := commute2).
+dependent destruction commute1;
+dependent destruction catchCommuteDetails;
+dependent destruction commute2;
+dependent destruction catchCommuteDetails generalizing X.
+Admitted.
\ No newline at end of file