X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Fsoftware%2Fmatita%2Flibrary%2Flogic%2Fcprop_connectives.ma;h=facda284891ed948ba1ed1e650e69c405fdd6b84;hb=3e094922bf3fec6975fdbe6feceb509eaafe0563;hp=c0bbdda18f3212715b49e5c8412cb7523c81e2ce;hpb=42c44d828983e4ea2d115eba20a8020b62108384;p=helm.git

diff --git a/helm/software/matita/library/logic/cprop_connectives.ma b/helm/software/matita/library/logic/cprop_connectives.ma
index c0bbdda18..facda2848 100644
--- a/helm/software/matita/library/logic/cprop_connectives.ma
+++ b/helm/software/matita/library/logic/cprop_connectives.ma
@@ -62,9 +62,17 @@ record Iff (A,B:CProp) : CProp ≝
  { if: A → B;
    fi: B → A
  }.
-
+ 
+record Iff1 (A,B:CProp) : CProp ≝
+ { if1: A → B;
+   fi1: B → A
+ }.
+ 
 interpretation "logical iff" 'iff x y = (Iff x y).
 
+notation "hvbox(a break ⇔ b)" right associative with precedence 25 for @{'iff1 $a $b}.
+interpretation "logical iff type1" 'iff1 x y = (Iff1 x y).
+
 inductive exT (A:Type) (P:A→CProp) : CProp ≝
   ex_introT: ∀w:A. P w → exT A P.