(* Basic_2A1: was: csx_fpb_conf *)
lemma csx_fpb_conf:
- â\88\80G1,L1,T1. â\9dªG1,L1â\9d« ⊢ ⬈*𝐒 T1 →
- â\88\80G2,L2,T2. â\9dªG1,L1,T1â\9d« â\89½ â\9dªG2,L2,T2â\9d« â\86\92 â\9dªG2,L2â\9d« ⊢ ⬈*𝐒 T2.
+ â\88\80G1,L1,T1. â\9d¨G1,L1â\9d© ⊢ ⬈*𝐒 T1 →
+ â\88\80G2,L2,T2. â\9d¨G1,L1,T1â\9d© â\89½ â\9d¨G2,L2,T2â\9d© â\86\92 â\9d¨G2,L2â\9d© ⊢ ⬈*𝐒 T2.
#G1 #L1 #T1 #HT1 #G2 #L2 #T2 #H
elim (fpb_inv_req … H) -H #L0 #L #T #H1 #HT2 #HL0 #HL02
lapply (cpx_reqg_conf … HL0 … HT2) -HT2 // #HT2