-lemma csx_fpb_conf: ∀h,o,G1,L1,T1. ⦃G1, L1⦄ ⊢ ⬊*[h, o] T1 →
- ∀G2,L2,T2. ⦃G1, L1, T1⦄ ≽[h, o] ⦃G2, L2, T2⦄ → ⦃G2, L2⦄ ⊢ ⬊*[h, o] T2.
-#h #o #G1 #L1 #T1 #HT1 #G2 #L2 #T2 *
-/2 width=5 by csx_cpx_trans, csx_fquq_conf, csx_lpx_conf, csx_lleq_conf/
-qed-.
-
-lemma csx_fpbs_conf: ∀h,o,G1,L1,T1. ⦃G1, L1⦄ ⊢ ⬊*[h, o] T1 →
- ∀G2,L2,T2. ⦃G1, L1, T1⦄ ≥[h, o] ⦃G2, L2, T2⦄ → ⦃G2, L2⦄ ⊢ ⬊*[h, o] T2.
-#h #o #G1 #L1 #T1 #HT1 #G2 #L2 #T2 #H @(fpbs_ind … H) -G2 -L2 -T2
+(* Basic_2A1: was: csx_fpbs_conf *)
+lemma fpbs_csx_conf:
+ ∀G1,L1,T1. ❨G1,L1❩ ⊢ ⬈*𝐒 T1 →
+ ∀G2,L2,T2. ❨G1,L1,T1❩ ≥ ❨G2,L2,T2❩ → ❨G2,L2❩ ⊢ ⬈*𝐒 T2.
+#G1 #L1 #T1 #HT1 #G2 #L2 #T2 #H @(fpbs_ind … H) -G2 -L2 -T2