1 (**************************************************************************)
4 (* ||A|| A project by Andrea Asperti *)
6 (* ||I|| Developers: *)
7 (* ||T|| The HELM team. *)
8 (* ||A|| http://helm.cs.unibo.it *)
10 (* \ / This file is distributed under the terms of the *)
11 (* v GNU General Public License Version 2 *)
13 (**************************************************************************)
15 set "baseuri" "cic:/matita/logic/iff".
17 definition Iff : Prop \to Prop \to Prop \def
18 \lambda A,B. (A \to B) \land (B \to A).
20 (*CSC: the URI must disappear: there is a bug now *)
21 interpretation "logical iff" 'iff x y = (cic:/matita/logic/iff/Iff.con x y).
23 notation < "hvbox(a break \liff b)"
24 left associative with precedence 25