-lemma lleq_cpx_trans: ∀h,g,G,L2,T1,T2. ⦃G, L2⦄ ⊢ T1 ➡[h, g] T2 →
- ∀L1. L1 ⋕[0, T1] L2 → ⦃G, L1⦄ ⊢ T1 ➡[h, g] T2.
-/4 width=6 by lleq_cpx_trans_leq, lleq_fwd_length, leq_O_Y/ qed-.
+lemma lleq_cpx_conf: ∀h,g,G,L2,T1,T2. ⦃G, L2⦄ ⊢ T1 ➡[h, g] T2 →
+ ∀L1. L2 ⋕[T1, 0] L1 → ⦃G, L1⦄ ⊢ T1 ➡[h, g] T2.
+/3 width=3 by lleq_cpx_trans, lleq_sym/ qed-.
+
+lemma lleq_cpx_conf_sn: ∀h,g,G. s_r_confluent1 … (cpx h g G) (lleq 0).
+/3 width=6 by llpx_sn_cpx_conf, lift_mono, ex2_intro/ qed-.
+
+lemma lleq_cpx_conf_dx: ∀h,g,G,L2,T1,T2. ⦃G, L2⦄ ⊢ T1 ➡[h, g] T2 →
+ ∀L1. L1 ⋕[T1, 0] L2 → L1 ⋕[T2, 0] L2.
+/4 width=6 by lleq_cpx_conf_sn, lleq_sym/ qed-.