Préférence donnée aux constantes qui ne sont pas des projections

canoniques lors d'une unification constante/constante s'apprêtant à
déplier l'une des deux constantes (suggestion des utilisateurs de
structures canoniques), ceci afin de préserver des possibilités
ultérieures de résolution d'evars par équipement en structure
canonique.



git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@11187 85f007b7-540e-0410-9357-904b9bb8a0f7

2 files changed, 22 insertions, 0 deletions

diff --git a/test-suite/success/CanonicalStructure.v b/test-suite/success/CanonicalStructure.v
index 44d21b83b..b8cae4719 100644
--- a/test-suite/success/CanonicalStructure.v
+++ b/test-suite/success/CanonicalStructure.v
@@ -12,3 +12,20 @@ Record Silly (X : Set) : Set := mkSilly { x : X }.
 Definition anotherMk := mkSilly.
 Definition struct := anotherMk nat 3.
 Canonical Structure struct.
+
+(* Intertwinning canonical structures and delta-expansion *)
+(* Assia's short example *)
+
+Open Scope bool_scope.
+
+Set Implicit Arguments.
+
+Structure test_struct : Type := mk_test {dom :> Type; f : dom -> dom -> bool}.
+
+Notation " x != y":= (f _ x y)(at level 10).
+
+Canonical Structure bool_test := mk_test (fun x y => x || y).
+
+Definition b := bool.
+
+Check (fun x : b => x != x).
diff --git a/test-suite/success/evars.v b/test-suite/success/evars.v
index 082cbfbe1..3bc9c7f9e 100644
--- a/test-suite/success/evars.v
+++ b/test-suite/success/evars.v
@@ -198,6 +198,11 @@ Goal forall x : nat, F1 x -> G1 x.
 refine (fun x H => proj2 (_ x H) _).
 Abort.
 
+(* First-order unification between beta-redex (is it useful ?) *)
+
+Check fun (y: (forall x:((fun y:Type => bool) nat), True))
+          (z: (fun z:Type => bool) _) => y z.
+
 (* Remark: the following example does not succeed any longer in 8.2 because,
    the algorithm is more general and does exclude a solution that it should
    exclude for typing reason. Handling of types and backtracking is still to