Fixing #4198 (continued): not matching within the inner lambdas/let-ins

of the return clause and of the branches (what assumed that the
implementation preserves the invariant that the return predicate and
the branches are in canonical [fun Δ => t] form, with Δ possibly
containing let-ins).

1 files changed, 26 insertions, 0 deletions

diff --git a/test-suite/success/ltac.v b/test-suite/success/ltac.v
index 6c4d4ae98..5bef2e512 100644
--- a/test-suite/success/ltac.v
+++ b/test-suite/success/ltac.v
@@ -317,3 +317,29 @@ let T := constr:(fun a b : nat => a) in
   end.
 exact (eq_refl n).
 Qed.
+
+(* Check that matching "match" does not look into the invisible
+   canonically generated binders of the return clause and of the branches *)
+
+Goal forall n, match n with 0 => true | S _ => false end = true.
+intros. unfold nat_rect.
+Fail match goal with |- context [nat] => idtac end.
+Abort.
+
+(* Check that branches of automatically generated elimination
+   principle are correctly eta-expanded and hence matchable as seen
+   from the user point of view *)
+
+Goal forall a f n, nat_rect (fun _ => nat) a f n = 0.
+intros. unfold nat_rect.
+match goal with |- context [f _] => idtac end.
+Abort.
+
+(* Check that branches of automatically generated elimination
+   principle are in correct form also in the presence of let-ins *)
+
+Inductive a (b:=0) : let b':=1 in Type := c : let d:=0 in a.
+Goal forall x, match x with c => 0 end = 1.
+intros.
+match goal with |- context [0] => idtac end.
+Abort.