(* *)
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+include "logic/connectives.ma".
+
inductive Or (A,B:CProp) : CProp ≝
| Left : A → Or A B
| Right : B → Or A B.
interpretation "constructive quaternary and" 'and4 x y z t = (And4 x y z t).
+record Iff (A,B:CProp) : CProp ≝
+ { if: A → B;
+ fi: B → A
+ }.
+
+interpretation "logical iff" 'iff x y = (Iff x y).
+
inductive exT (A:Type) (P:A→CProp) : CProp ≝
ex_introT: ∀w:A. P w → exT A P.
inductive exT2 (A:Type) (P,Q:A→CProp) : CProp ≝
ex_introT2: ∀w:A. P w → Q w → exT2 A P Q.
-alias id "False" = "cic:/Coq/Init/Logic/False.ind#xpointer(1/1)".
definition Not : CProp → Prop ≝ λx:CProp.x → False.
interpretation "constructive not" 'not x = (Not x).