aboutsummaryrefslogtreecommitdiff
path: root/theories/Logic/Description.v
blob: 9b86e2679073d8840cfdfe5f6172b297512392c8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
(************************************************************************)
(*         *   The Coq Proof Assistant / The Coq Development Team       *)
(*  v      *         Copyright INRIA, CNRS and contributors             *)
(* <O___,, * (see version control and CREDITS file for authors & dates) *)
(*   \VV/  **************************************************************)
(*    //   *    This file is distributed under the terms of the         *)
(*         *     GNU Lesser General Public License Version 2.1          *)
(*         *     (see LICENSE file for the text of the license)         *)
(************************************************************************)

(** 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 }.