summaryrefslogtreecommitdiff
path: root/theories/Logic/RelationalChoice.v
blob: 11979057e27b40c8eae569bbd3a2fed77e1a5d6f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
(************************************************************************)
(*  v      *   The Coq Proof Assistant  /  The Coq Development Team     *)
(* <O___,, * CNRS-Ecole Polytechnique-INRIA Futurs-Universite Paris Sud *)
(*   \VV/  **************************************************************)
(*    //   *      This file is distributed under the terms of the       *)
(*         *       GNU Lesser General Public License Version 2.1        *)
(************************************************************************)

(*i $Id: RelationalChoice.v 6001 2004-08-01 09:27:26Z herbelin $ i*)

(** This file axiomatizes the relational form of the axiom of choice *)

Axiom
  relational_choice :
    forall (A B:Type) (R:A -> B -> Prop),
      (forall x:A,  exists y : B, R x y) ->
       exists R' : A -> B -> Prop,
        (forall x:A,
            exists y : B,
             R x y /\ R' x y /\ (forall y':B, R' x y' -> y = y')).