(* Note: apparently this was missing in basic_1 *)
lemma cprs_delta: ∀G,L,K,V,V2,i.
- â\87©[i] L ≡ K.ⓓV → ⦃G, K⦄ ⊢ V ➡* V2 →
- â\88\80W2. â\87§[0, i + 1] V2 ≡ W2 → ⦃G, L⦄ ⊢ #i ➡* W2.
+ â¬\87[i] L ≡ K.ⓓV → ⦃G, K⦄ ⊢ V ➡* V2 →
+ â\88\80W2. â¬\86[0, i + 1] V2 ≡ W2 → ⦃G, L⦄ ⊢ #i ➡* W2.
#G #L #K #V #V2 #i #HLK #H elim H -V2 [ /3 width=6 by cpr_cprs, cpr_delta/ ]
#V1 #V2 #_ #HV12 #IHV1 #W2 #HVW2
lapply (drop_fwd_drop2 … HLK) -HLK #HLK
(* Basic_1: was: pr3_gen_lref *)
lemma cprs_inv_lref1: ∀G,L,T2,i. ⦃G, L⦄ ⊢ #i ➡* T2 →
T2 = #i ∨
- â\88\83â\88\83K,V1,T1. â\87©[i] L ≡ K.ⓓV1 & ⦃G, K⦄ ⊢ V1 ➡* T1 &
- â\87§[0, i + 1] T1 ≡ T2.
+ â\88\83â\88\83K,V1,T1. â¬\87[i] L ≡ K.ⓓV1 & ⦃G, K⦄ ⊢ V1 ➡* T1 &
+ â¬\86[0, i + 1] T1 ≡ T2.
#G #L #T2 #i #H @(cprs_ind … H) -T2 /2 width=1 by or_introl/
#T #T2 #_ #HT2 *
[ #H destruct