X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Fsoftware%2Fmatita%2Flibrary%2Flogic%2Fconnectives.ma;h=5afc3e5dc29d7db0f45e812d244f6cd72e4ff7f6;hb=f79585fe2f19c4a545938e189439d87b2611a47a;hp=4cbea3529a7ec983b39f814f1243f1a5f92568ab;hpb=55b82bd235d82ff7f0a40d980effe1efde1f5073;p=helm.git

diff --git a/helm/software/matita/library/logic/connectives.ma b/helm/software/matita/library/logic/connectives.ma
index 4cbea3529..5afc3e5dc 100644
--- a/helm/software/matita/library/logic/connectives.ma
+++ b/helm/software/matita/library/logic/connectives.ma
@@ -79,12 +79,8 @@ inductive ex (A:Type) (P:A \to Prop) : Prop \def
 interpretation "exists" 'exists \eta.x =
   (cic:/matita/logic/connectives/ex.ind#xpointer(1/1) _ x).
 
-notation < "hvbox(\exists ident i opt (: ty) break . p)"
-  right associative with precedence 20
-for @{ 'exists ${default
-  @{\lambda ${ident i} : $ty. $p)}
-  @{\lambda ${ident i} . $p}}}.
-
 inductive ex2 (A:Type) (P,Q:A \to Prop) : Prop \def
     ex_intro2: \forall x:A. P x \to Q x \to ex2 A P Q.
 
+definition iff :=
+ \lambda A,B. (A -> B) \land (B -> A).
\ No newline at end of file