1 (**************************************************************************)
4 (* ||A|| A project by Andrea Asperti *)
6 (* ||I|| Developers: *)
7 (* ||T|| The HELM team. *)
8 (* ||A|| http://helm.cs.unibo.it *)
10 (* \ / This file is distributed under the terms of the *)
11 (* v GNU General Public License Version 2 *)
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15 include "ground_2/lib/relations.ma".
17 (* FUNCTIONS ****************************************************************)
19 definition left_identity (A:Type[0]) (f): predicate A ≝ λi. ∀a:A. a = f i a.
21 definition right_identity (A:Type[0]) (f): predicate A ≝ λi. ∀a:A. a = f a i.