/3 width=5 by lpxs_pair, cpxs_trans, cpxs_strap1, ex3_2_intro/
qed-.
-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/
#U0 #U2 #_ #HU02 * *
[ #V0 #T0 #HV10 #HT10 #H destruct
elim (cpx_inv_abbr1 … HU02) -HU02 *
[ #V2 #T2 #HV02 #HT02 #H destruct
lapply (lpxs_cpx_trans … HT02 (L.ⓓV1) ?)
/4 width=5 by lpxs_pair, cpxs_trans, cpxs_strap1, ex3_2_intro, or_introl/
- | #T2 #HT02 #HUT2
- lapply (lpxs_cpx_trans … HT02 (L.ⓓV1) ?) -HT02
- /4 width=3 by lpxs_pair, cpxs_trans, ex3_intro, or_intror/
+ | #T2 #HT20 #HTU2 #Hp -V0
+ elim (cpx_lifts_sn … HTU2 (Ⓣ) … (L.ⓓV1) … HT20) -T2 [| /3 width=3 by drops_refl, drops_drop/ ] #U0 #HU20 #HTU0
+ /4 width=3 by cpxs_strap1, ex3_intro, or_intror/
]
| #U1 #HTU1 #HU01 #Hp
- elim (cpx_lifts_sn … HU02 (Ⓣ) … (L.ⓓV1) … HU01) -U0 /3 width=3 by drops_refl, drops_drop/ #U #HU2 #HU1
+ elim (cpx_lifts_sn … HU02 (Ⓣ) … (L.ⓓV1) … HU01) -U0 [| /3 width=3 by drops_refl, drops_drop/ ] #U #HU2 #HU1
/4 width=3 by cpxs_strap1, ex3_intro, or_intror/
]
qed-.