]> matita.cs.unibo.it Git - helm.git/blob - matita/matita/contribs/LOGIC/Weight/defs.ma
update in delayed-updating
[helm.git] / matita / matita / contribs / LOGIC / Weight / defs.ma
1 (**************************************************************************)
2 (*       ___                                                              *)
3 (*      ||M||                                                             *)
4 (*      ||A||       A project by Andrea Asperti                           *)
5 (*      ||T||                                                             *)
6 (*      ||I||       Developers:                                           *)
7 (*      ||T||         The HELM team.                                      *)
8 (*      ||A||         http://helm.cs.unibo.it                             *)
9 (*      \   /                                                             *)
10 (*       \ /        This file is distributed under the terms of the       *)
11 (*        v         GNU General Public License Version 2                  *)
12 (*                                                                        *)
13 (**************************************************************************)
14
15
16
17 (* PROOF WEIGHT
18    For cut elimination and confluence
19 *)
20
21 include "datatypes_defs/Context.ma".
22
23
24 inductive Weight: Nat \to Context \to Proof \to Nat \to Prop \def
25    | weight_prin: \forall Q,n,m. Weight m Q (prin n) m
26    | weight_impw: \forall p,Q,m0,m1. Weight m0 Q p m1 \to
27                   \forall m. (m1 + m0 == m) \to
28                   Weight m0 Q (impw p) m
29    | weight_impr: \forall p,Q,m0,m1. Weight m0 Q p m1 \to
30                   \forall m. (m1 + m0 == m) \to
31                   Weight m0 Q (impr p) m
32    | weight_scut: \forall p1,Q,m0,m1. Weight (succ m0) Q p1 m1 \to
33                   \forall p2,m2. Weight (succ m0) Q p2 m2 \to
34                   \forall m. (m1 + m2 == m) \to
35                   Weight m0 Q (scut p1 p2) m
36 .