(* Properties with generic slicing for local environments *******************)
-lemma fqus_drops: ∀b,G,L,K,T,U,i. ⇩*[i] L ≘ K → ⇧*[i] T ≘ U →
+lemma fqus_drops: ∀b,G,L,K,T,U,i. ⇩[i] L ≘ K → ⇧[i] T ≘ U →
❪G,L,U❫ ⬂*[b] ❪G,K,T❫.
#b #G #L #K #T #U * /3 width=3 by fqup_drops_succ, fqup_fqus/
#HLK #HTU <(lifts_fwd_isid … HTU) -U // <(drops_fwd_isid … HLK) -K //