-lemma cpxs_inv_abbr1 (h) (G): ∀p,L,V1,T1,U2. ⦃G, L⦄ ⊢ ⓓ{p}V1.T1 ⬈*[h] U2 →
- ∨∨ ∃∃V2,T2. ⦃G, L⦄ ⊢ V1 ⬈*[h] V2 & ⦃G, L.ⓓV1⦄ ⊢ T1 ⬈*[h] T2 &
- U2 = ⓓ{p}V2.T2
- | ∃∃T2. ⦃G, L.ⓓV1⦄ ⊢ T1 ⬈*[h] T2 & ⬆*[1] U2 ≘ T2 & p = Ⓣ.
-#h #G #p #L #V1 #T1 #U2 #H @(cpxs_ind … H) -U2 /3 width=5 by ex3_2_intro, or_introl/
+(* Basic_2A1: was: cpxs_inv_abbr1 *)
+lemma cpxs_inv_abbr1_dx (h) (p) (G) (L):
+ ∀V1,T1,U2. ❪G,L❫ ⊢ ⓓ[p]V1.T1 ⬈*[h] U2 →
+ ∨∨ ∃∃V2,T2. ❪G,L❫ ⊢ V1 ⬈*[h] V2 & ❪G,L.ⓓV1❫ ⊢ T1 ⬈*[h] T2 &
+ U2 = ⓓ[p]V2.T2
+ | ∃∃T2. ❪G,L.ⓓV1❫ ⊢ T1 ⬈*[h] T2 & ⇧[1] U2 ≘ T2 & p = Ⓣ.
+#h #p #G #L #V1 #T1 #U2 #H
+@(cpxs_ind … H) -U2 /3 width=5 by ex3_2_intro, or_introl/