Revision of the FSetWeak Interface, so that it becomes a precise

subtype of the FSet Interface (and idem for FMapWeak / FMap). 

1) No eq_dec is officially required in FSetWeakInterface.S.E
(EqualityType instead of DecidableType). But of course,
implementations still needs this eq_dec. 

2) elements_3 differs in FSet and FSetWeak (sort vs. nodup). In
FSetWeak we rename it into elements_3w, whereas in FSet we
artificially add elements_3w along to the original elements_3.

Initial steps toward factorization of FSetFacts and FSetWeakFacts, 
and so on...

Even if it's not required, FSetWeakList provides a eq_dec on sets, 
allowing weak sets of weak sets. 





git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@10271 85f007b7-540e-0410-9357-904b9bb8a0f7

1 files changed, 3 insertions, 0 deletions

diff --git a/theories/FSets/FMapInterface.v b/theories/FSets/FMapInterface.v
index d4e07461c..c235976bd 100644
--- a/theories/FSets/FMapInterface.v
+++ b/theories/FSets/FMapInterface.v
@@ -161,6 +161,9 @@ Module Type S.
       Parameter elements_2 : 
         InA eq_key_elt (x,e) (elements m) -> MapsTo x e m.
       Parameter elements_3 : sort lt_key (elements m).  
+      (* We add artificially elements_3w, a weaker version of 
+         elements_3, for allowing FMapWeak < FMap subtyping. *)
+      Parameter elements_3w : NoDupA eq_key (elements m).  
 
     (** Specification of [fold] *)  
       Parameter fold_1 :