(* *)
(**************************************************************************)
-set "baseuri" "cic:/matita/logic/connectives/".
-
inductive True: Prop \def
I : True.
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).