Library Coq.Logic.PropExtensionality


This module states propositional extensionality and draws consequences of it

Axiom propositional_extensionality :
  forall (P Q : Prop), (P <-> Q) -> P = Q.

Require Import ClassicalFacts.

Theorem proof_irrelevance : forall (P:Prop) (p1 p2:P), p1 = p2.