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 *)
13 (**************************************************************************)
15 include "pointer_order.ma".
17 (* POINTER SEQUENCE *********************************************************)
19 (* Policy: pointer sequence metavariables: r, s *)
20 definition pseq: Type[0] ≝ list ptr.
22 (* Note: a "head" computation contracts just redexes in the head *)
23 definition is_head: predicate pseq ≝ All … in_head.
25 (* Note: to us, a "normal" computation contracts redexes in non-decreasing positions *)
26 definition is_le: predicate pseq ≝ Allr … ple.