(* Basic_1: was: csubc_drop1_conf_rev *)
lemma ldrops_lsubc_trans: ∀RR,RS,RP.
acp RR RS RP → acr RR RS RP (λG,L,T. RP G L T) →
- â\88\80G,L1,K1,des. â\87©*[â\92», des] L1 â\89¡ K1 â\86\92 â\88\80K2. G â\8a¢ K1 â\8a\91[RP] K2 →
- â\88\83â\88\83L2. G â\8a¢ L1 â\8a\91[RP] L2 & ⇩*[Ⓕ, des] L2 ≡ K2.
+ â\88\80G,L1,K1,des. â\87©*[â\92», des] L1 â\89¡ K1 â\86\92 â\88\80K2. G â\8a¢ K1 â«\83[RP] K2 →
+ â\88\83â\88\83L2. G â\8a¢ L1 â«\83[RP] L2 & ⇩*[Ⓕ, des] L2 ≡ K2.
#RR #RS #RP #Hacp #Hacr #G #L1 #K1 #des #H elim H -L1 -K1 -des
[ /2 width=3 by ldrops_nil, ex2_intro/
| #L1 #L #K1 #des #d #e #_ #HLK1 #IHL #K2 #HK12