--- /dev/null
+(**************************************************************************)
+(* ___ *)
+(* ||M|| *)
+(* ||A|| A project by Andrea Asperti *)
+(* ||T|| *)
+(* ||I|| Developers: *)
+(* ||T|| The HELM team. *)
+(* ||A|| http://helm.cs.unibo.it *)
+(* \ / *)
+(* \ / This file is distributed under the terms of the *)
+(* v GNU General Public License Version 2 *)
+(* *)
+(**************************************************************************)
+
+(* STATO: COMPILA *)
+
+set "baseuri" "cic:/matita/logic/iff".
+
+include "../../library/logic/connectives.ma".
+
+definition Iff : Prop \to Prop \to Prop \def
+ \lambda A,B. (A \to B) \land (B \to A).
+
+ (*CSC: the URI must disappear: there is a bug now *)
+interpretation "logical iff" 'iff x y = (cic:/matita/logic/iff/Iff.con x y).
+
+notation > "hvbox(a break \liff b)"
+ left associative with precedence 25
+for @{ 'iff $a $b }.
+
+notation < "hvbox(a break \leftrightarrow b)"
+ left associative with precedence 25
+for @{ 'iff $a $b }.