elim (cpx_tdeq_conf … HT01 T2) -HT01 /3 width=3 by tdeq_sym, ex2_intro/
qed-.
-(* Basic_2A1: was just: cpx_lleq_conf *)
+(* Basic_2A1: uses: cpx_lleq_conf *)
lemma cpx_lfdeq_conf: ∀h,o,G,L0,T0,T1. ⦃G, L0⦄ ⊢ T0 ⬈[h] T1 →
∀L2. L0 ≡[h, o, T0] L2 →
∃∃T. ⦃G, L2⦄ ⊢ T0 ⬈[h] T & T1 ≡[h, o] T.
/2 width=3 by lfxs_refl, ex2_intro/
qed-.
-(* Basic_2A1: was just: lleq_cpx_trans *)
+(* Basic_2A1: uses: lleq_cpx_trans *)
lemma lfdeq_cpx_trans: ∀h,o,G,L2,L0,T0. L2 ≡[h, o, T0] L0 →
∀T1. ⦃G, L0⦄ ⊢ T0 ⬈[h] T1 →
∃∃T. ⦃G, L2⦄ ⊢ T0 ⬈[h] T & T ≡[h, o] T1.
lemma lfpx_lfdeq_conf: ∀h,o,G,T. confluent2 … (lfpx h G T) (lfdeq h o T).
/3 width=6 by lfpx_frees_conf, cpx_tdeq_conf_lexs, frees_lfdeq_conf_lexs, lfxs_conf/ qed-.
-(* Basic_2A1: was just: lleq_lpx_trans *)
+(* Basic_2A1: uses: lleq_lpx_trans *)
lemma lfdeq_lfpx_trans: ∀h,o,G,T,L2,K2. ⦃G, L2⦄ ⊢ ⬈[h, T] K2 →
∀L1. L1 ≡[h, o, T] L2 →
∃∃K1. ⦃G, L1⦄ ⊢ ⬈[h, T] K1 & K1 ≡[h, o, T] K2.