]> matita.cs.unibo.it Git - helm.git/blob - matita/matita/contribs/lambdadelta/basic_2/etc_2A1/cpr/cpr_ltpss_dx.etc
- degree-based equivalene for terms
[helm.git] / matita / matita / contribs / lambdadelta / basic_2 / etc_2A1 / cpr / cpr_ltpss_dx.etc
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 include "basic_2/unfold/ltpss_dx_ltpss_dx.ma".
16 include "basic_2/reducibility/cpr.ma".
17
18 (* CONTEXT-SENSITIVE PARALLEL REDUCTION ON TERMS ****************************)
19
20 (* Properties concerning dx partial unfold on local environments ************)
21
22 lemma ltpss_dx_cpr_conf: ∀L1,T,U1. L1 ⊢ T ➡ U1 →
23                          ∀L2,d,e. L1 ▶* [d, e] L2 →
24                          ∃∃U2. L2 ⊢ T ➡ U2 & L2 ⊢ U1 ▶* [d, e] U2.
25 #L1 #T #U1 * #U #HTU #HU1 #L2 #d #e #HL12
26 lapply (ltpss_dx_fwd_length … HL12) #H >H in HU1; -H #HU1
27 elim (ltpss_dx_tpss_conf … HU1 … HL12) -L1 /3 width=3/
28 qed-.