(* *)
(**************************************************************************)
-include "basic_2/unwind/sstas.ma".
+include "basic_2/unfold/sstas.ma".
include "basic_2/computation/cprs.ma".
(* DECOMPOSED EXTENDED PARALLEL COMPUTATION ON TERMS ************************)
∃∃T. ⦃h, L⦄ ⊢ T1 •*[g] T & L ⊢ T ➡* T2.
interpretation "decomposed extended parallel computation (term)"
- 'DecomposedXPRedStar h g L T1 T2 = (dxprs h g L T1 T2).
+ 'DecomposedPRedStar h g L T1 T2 = (dxprs h g L T1 T2).
(* Basic properties *********************************************************)
⦃h, L⦄ ⊢ T1 •[g] ⦃l+1, T⦄ → ⦃h, L⦄ ⊢ T •*➡*[g] T2 → ⦃h, L⦄ ⊢ T1 •*➡*[g] T2.
#h #g #L #T1 #T #T2 #l #HT1 * /3 width=4/
qed.
+
+lemma ssta_cprs_dxprs: ∀h,g,L,T1,T,T2,l. ⦃h, L⦄ ⊢ T1 •[g] ⦃l+1, T⦄ →
+ L ⊢ T ➡* T2 → ⦃h, L⦄ ⊢ T1 •*➡*[g] T2.
+/3 width=3/ qed.
+
+(* Basic inversion lemmas ***************************************************)
+
+lemma dxprs_inv_abst1: ∀h,g,a,L,V1,T1,U2. ⦃h, L⦄ ⊢ ⓛ{a}V1. T1 •*➡*[g] U2 →
+ ∃∃V2,T2. L ⊢ V1 ➡* V2 & ⦃h, L.ⓛV1⦄ ⊢ T1 •*➡*[g] T2 &
+ U2 = ⓛ{a}V2. T2.
+#h #g #a #L #V1 #T1 #U2 * #X #H1 #H2
+elim (sstas_inv_bind1 … H1) -H1 #U #HTU1 #H destruct
+elim (cprs_fwd_abst1 … H2 Abst V1) -H2 #V2 #T2 #HV12 #HUT2 #H destruct /3 width=5/
+qed-.