]> matita.cs.unibo.it Git - helm.git/blobdiff - helm/software/matita/library/logic/connectives.ma
more push/pop to avoid confusion with imperative data structures employed by
[helm.git] / helm / software / matita / library / logic / connectives.ma
index bb08b8038bf51c37d533a0889c2493fd04fdc810..ba229870fbca66c1a860268d30dc9e0e0301b137 100644 (file)
@@ -12,8 +12,6 @@
 (*                                                                        *)
 (**************************************************************************)
 
-set "baseuri" "cic:/matita/logic/connectives/".
-
 inductive True: Prop \def
 I : True.
 
@@ -82,3 +80,5 @@ interpretation "exists" 'exists \eta.x =
 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).