The Coq Proof Assistant

# Library Coq.Logic.Description

This file provides a constructive form of definite description; it allows building functions from the proof of their existence in any context; this is weaker than Church's iota operator
Require Import ChoiceFacts.
Set Implicit Arguments.
Axiom constructive_definite_description :
forall (A : Type) (P : A->Prop),
(exists! x, P x) -> { x : A | P x }.