∃∃L2. L1 ⪤[R] L2 & ⇩*[b,f] L2 ≘ K2 & L1 ≡[f] L2.
definition dropable_sn: predicate … ≝
- λR. â\88\80b,f,L1,K1. â\87©*[b,f] L1 â\89\98 K1 â\86\92 ð\9d\90\94â¦\83fâ¦\84 → ∀L2. L1 ⪤[R] L2 →
+ λR. â\88\80b,f,L1,K1. â\87©*[b,f] L1 â\89\98 K1 â\86\92 ð\9d\90\94â\9dªfâ\9d« → ∀L2. L1 ⪤[R] L2 →
∃∃K2. K1 ⪤[R] K2 & ⇩*[b,f] L2 ≘ K2.
definition dropable_dx: predicate … ≝
- λR. â\88\80L1,L2. L1 ⪤[R] L2 â\86\92 â\88\80b,f,K2. â\87©*[b,f] L2 â\89\98 K2 â\86\92 ð\9d\90\94â¦\83fâ¦\84 →
+ λR. â\88\80L1,L2. L1 ⪤[R] L2 â\86\92 â\88\80b,f,K2. â\87©*[b,f] L2 â\89\98 K2 â\86\92 ð\9d\90\94â\9dªfâ\9d« →
∃∃K1. ⇩*[b,f] L1 ≘ K1 & K1 ⪤[R] K2.
(* Properties with generic extension ****************************************)
(* Basic_2A1: includes: lpx_sn_drop_conf *)
lemma lex_drops_conf_pair (R): ∀L1,L2. L1 ⪤[R] L2 →
- ∀b,f,I,K1,V1. ⇩*[b,f] L1 ≘ K1.ⓑ{I}V1 → 𝐔⦃f⦄ →
- ∃∃K2,V2. ⇩*[b,f] L2 ≘ K2.ⓑ{I}V2 & K1 ⪤[R] K2 & R K1 V1 V2.
+ ∀b,f,I,K1,V1. ⇩*[b,f] L1 ≘ K1.ⓑ[I]V1 → 𝐔❪f❫ →
+ ∃∃K2,V2. ⇩*[b,f] L2 ≘ K2.ⓑ[I]V2 & K1 ⪤[R] K2 & R K1 V1 V2.
#R #L1 #L2 * #f2 #Hf2 #HL12 #b #f #I #K1 #V1 #HLK1 #Hf
elim (sex_drops_conf_push … HL12 … HLK1 Hf f2) -L1 -Hf
[ #Z2 #K2 #HLK2 #HK12 #H
(* Basic_2A1: includes: lpx_sn_drop_trans *)
lemma lex_drops_trans_pair (R): ∀L1,L2. L1 ⪤[R] L2 →
- ∀b,f,I,K2,V2. ⇩*[b,f] L2 ≘ K2.ⓑ{I}V2 → 𝐔⦃f⦄ →
- ∃∃K1,V1. ⇩*[b,f] L1 ≘ K1.ⓑ{I}V1 & K1 ⪤[R] K2 & R K1 V1 V2.
+ ∀b,f,I,K2,V2. ⇩*[b,f] L2 ≘ K2.ⓑ[I]V2 → 𝐔❪f❫ →
+ ∃∃K1,V1. ⇩*[b,f] L1 ≘ K1.ⓑ[I]V1 & K1 ⪤[R] K2 & R K1 V1 V2.
#R #L1 #L2 * #f2 #Hf2 #HL12 #b #f #I #K2 #V2 #HLK2 #Hf
elim (sex_drops_trans_push … HL12 … HLK2 Hf f2) -L2 -Hf
[ #Z1 #K1 #HLK1 #HK12 #H