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4 (* ||A|| A project by Andrea Asperti *)
6 (* ||I|| Developers: *)
7 (* ||T|| The HELM team. *)
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15 include "basic_2/notation/relations/predstar_7.ma".
16 include "basic_2/dynamic/cnv_cpm_trans.ma".
17 include "basic_2/dynamic/cnv_cpm_conf.ma".
19 (* CONTEXT-SENSITIVE NATIVE VALIDITY FOR TERMS ******************************)
21 definition cpsms (n) (h) (o): relation4 genv lenv term term ≝ λG,L,T1,T2.
22 ∃∃n1,n2,T. T1 ≛[h,o] T → ⊥ & ⦃G, L⦄ ⊢ T1 ➡[n1,h] T & ⦃G, L⦄ ⊢ T ➡*[n2,h] T2 & n1+n2 = n.
25 "context-sensitive parallel stratified t-bound rt-computarion (term)"
26 'PRedStar n h o G L T1 T2 = (cpsms n h o G L T1 T2).
28 definition IH_cnv_cpsms_conf_lpr (a) (h) (o): relation3 genv lenv term ≝
29 λG,L0,T0. ⦃G, L0⦄ ⊢ T0 ![a,h] →
30 ∀n1,T1. ⦃G, L0⦄ ⊢ T0 ➡*[n1,h,o] T1 → ∀n2,T2. ⦃G, L0⦄ ⊢ T0 ➡*[n2,h,o] T2 →
31 ∀L1. ⦃G, L0⦄ ⊢ ➡[h] L1 → ∀L2. ⦃G, L0⦄ ⊢ ➡[h] L2 →
32 ∃∃T. ⦃G, L1⦄ ⊢ T1 ➡*[n2-n1,h] T & ⦃G, L2⦄ ⊢ T2 ➡*[n1-n2,h] T.
34 (* Sub confluence propery with t-bound rt-computation for terms *************)
36 fact cnv_cpsms_conf_lpr_aux (a) (h) (o):
38 (∀G1,L1,T1. ⦃G0, L0, T0⦄ >[h, o] ⦃G1, L1, T1⦄ → IH_cnv_cpm_trans_lpr a h G1 L1 T1) →
39 (∀G1,L1,T1. ⦃G0, L0, T0⦄ >[h, o] ⦃G1, L1, T1⦄ → IH_cnv_cpms_conf_lpr a h G1 L1 T1) →
40 ∀G1,L1,T1. G0 = G1 → L0 = L1 → T0 = T1 → IH_cnv_cpsms_conf_lpr a h o G1 L1 T1.
41 #a #h #o #G #L #T #IH2 #IH1 #G0 #L0 #T0 #HG #HL #HT #HT0
42 #n1 #T1 * #m11 #m12 #X1 #HnX01 #HX01 #HXT1 #H1
43 #n2 #T2 * #m21 #m22 #X2 #HnX02 #HX02 #HXT2 #H2
44 #L1 #HL01 #L2 #HL02 destruct
45 lapply (cnv_cpm_trans_lpr_aux … IH1 IH2 … HX01 … L0 ?) // #HX1
46 lapply (cnv_cpm_trans_lpr_aux … IH1 IH2 … HX02 … L0 ?) // #HX2
47 elim (cnv_cpm_conf_lpr_aux … IH2 IH1 … HX01 … HX02 … L0 … L0) // #Z0 #HXZ10 #HXZ20
48 cut (⦃G0,L0,T0⦄ >[h,o] ⦃G0,L0,X1⦄) [ /4 width=5 by cpms_fwd_fpbs, cpm_fpb, ex2_3_intro/ ] #H1fpbg (**) (* cut *)
49 lapply (fpbg_fpbs_trans ??? G0 ? L0 ? Z0 ? … H1fpbg) [ /2 width=2 by cpms_fwd_fpbs/ ] #H2fpbg
50 lapply (cnv_cpms_trans_lpr_sub … IH2 … HXZ10 … L0 ?) // #HZ0
51 elim (IH1 … HXT1 … HXZ10 … L1 … L0) [|*: /4 width=2 by fpb_fpbg, cpm_fpb/ ] -HXT1 -HXZ10 #Z1 #HTZ1 #HZ01
52 elim (IH1 … HXT2 … HXZ20 … L2 … L0) [|*: /4 width=2 by fpb_fpbg, cpm_fpb/ ] -HXT2 -HXZ20 #Z2 #HTZ2 #HZ02
53 elim (IH1 … HZ01 … HZ02 L1 … L2) // -L0 -T0 -X1 -X2 -Z0 #Z #HZ01 #HZ02
54 lapply (cpms_trans … HTZ1 … HZ01) -Z1 <arith_l4 #HT1Z
55 lapply (cpms_trans … HTZ2 … HZ02) -Z2 <arith_l4 #HT2Z
56 /2 width=3 by ex2_intro/