(* Basic_2A1: includes: lreq_drop_trans_be *)
lemma seq_drops_trans_next: ∀f2,L1,L2. L1 ≡[f2] L2 →
- ∀b,f,I,K2. ⇩*[b,f] L2 ≘ K2.ⓘ{I} → 𝐔⦃f⦄ →
+ ∀b,f,I,K2. ⇩*[b,f] L2 ≘ K2.ⓘ[I] → 𝐔❪f❫ →
∀f1. f ~⊚ ↑f1 ≘ f2 →
- ∃∃K1. ⇩*[b,f] L1 ≘ K1.ⓘ{I} & K1 ≡[f1] K2.
+ ∃∃K1. ⇩*[b,f] L1 ≘ K1.ⓘ[I] & K1 ≡[f1] K2.
#f2 #L1 #L2 #HL12 #b #f #I2 #K2 #HLK2 #Hf #f1 #Hf2
elim (sex_drops_trans_next … HL12 … HLK2 Hf … Hf2) -f2 -L2 -Hf
#I1 #K1 #HLK1 #HK12 #H <(ceq_ext_inv_eq … H) -I2
(* Basic_2A1: includes: lreq_drop_conf_be *)
lemma seq_drops_conf_next: ∀f2,L1,L2. L1 ≡[f2] L2 →
- ∀b,f,I,K1. ⇩*[b,f] L1 ≘ K1.ⓘ{I} → 𝐔⦃f⦄ →
+ ∀b,f,I,K1. ⇩*[b,f] L1 ≘ K1.ⓘ[I] → 𝐔❪f❫ →
∀f1. f ~⊚ ↑f1 ≘ f2 →
- ∃∃K2. ⇩*[b,f] L2 ≘ K2.ⓘ{I} & K1 ≡[f1] K2.
+ ∃∃K2. ⇩*[b,f] L2 ≘ K2.ⓘ[I] & K1 ≡[f1] K2.
#f2 #L1 #L2 #HL12 #b #f #I1 #K1 #HLK1 #Hf #f1 #Hf2
elim (seq_drops_trans_next … (seq_sym … HL12) … HLK1 … Hf2) // -f2 -L1 -Hf
/3 width=3 by seq_sym, ex2_intro/
qed-.
lemma drops_seq_trans_next: ∀f1,K1,K2. K1 ≡[f1] K2 →
- ∀b,f,I,L1. ⇩*[b,f] L1.ⓘ{I} ≘ K1 →
+ ∀b,f,I,L1. ⇩*[b,f] L1.ⓘ[I] ≘ K1 →
∀f2. f ~⊚ f1 ≘ ↑f2 →
- ∃∃L2. ⇩*[b,f] L2.ⓘ{I} ≘ K2 & L1 ≡[f2] L2 & L1.ⓘ{I} ≡[f] L2.ⓘ{I}.
+ ∃∃L2. ⇩*[b,f] L2.ⓘ[I] ≘ K2 & L1 ≡[f2] L2 & L1.ⓘ[I] ≡[f] L2.ⓘ[I].
#f1 #K1 #K2 #HK12 #b #f #I1 #L1 #HLK1 #f2 #Hf2
elim (drops_sex_trans_next … HK12 … HLK1 … Hf2) -f1 -K1
/2 width=6 by cfull_lift_sn, ceq_lift_sn/