Clarification des contraintes sur le contexte de paramètres des

inductifs dans le test de sous-typage (exigence du même nombre
d'arguments uniformes attendus mais pas d'exigence spéciale sur les
définitions locales du contexte à partir du moment où les types et
constructeurs sont convertibles quand généralisés par rapport au
contexte de paramètres)


git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@9247 85f007b7-540e-0410-9357-904b9bb8a0f7

2 files changed, 12 insertions, 3 deletions

diff --git a/kernel/subtyping.ml b/kernel/subtyping.ml
index 0acd37da4e..c94219316b 100644
--- a/kernel/subtyping.ml
+++ b/kernel/subtyping.ml
@@ -94,7 +94,7 @@ let check_inductive cst env msid1 l info1 mib2 spec2 =
       (* listrec ignored *)
       (* finite done *)
       (* nparams done *)
-      (* params_ctxt done *)
+      (* params_ctxt done because part of the inductive types *)
       (* Don't check the sort of the type if polymorphic *)
       let cst = check_conv cst conv env (type_of_inductive (mib1,p1)) (type_of_inductive (mib2,p2))
       in
@@ -114,9 +114,12 @@ let check_inductive cst env msid1 l info1 mib2 spec2 =
   assert (Array.length mib1.mind_packets >= 1 
 	    && Array.length mib2.mind_packets >= 1);
 
-       (* TODO: we should allow renaming of parameters at least ! *)
+  (* Check that the expected numbers of uniform parameters are the same *)
+  (* No need to check the contexts of parameters: it is checked *)
+  (* at the time of checking the inductive arities in check_packet. *)
+  (* Notice that we don't expect the local definitions to match: only *)
+  (* the inductive types and constructors types have to be convertible *)
   check (fun mib -> mib.mind_nparams);
-  check (fun mib -> mib.mind_params_ctxt); 
 
   begin 
     match mib2.mind_equiv with
diff --git a/test-suite/modules/ind.v b/test-suite/modules/ind.v
index a15f390a38..3af94c3b91 100644
--- a/test-suite/modules/ind.v
+++ b/test-suite/modules/ind.v
@@ -41,3 +41,9 @@ Check (N.f M.A).
 
   End C.
 
+(* Check subtyping of the context of parameters of the inductive types *)
+(* Only the number of expected uniform parameters and the convertibility *)
+(* of the inductive arities and constructors types are checked *)
+
+Module Type S. Inductive I (x:=0) (y:nat): Set := c: x=y -> I y. End S.
+Module P : S.  Inductive I (y':nat) (z:=y'): Set := c : 0=y' -> I y'. End P.