-(* Note: this is used in the closure proof *)
-lemma fpbg_fpbs_trans: ∀h,o,G,G2,L,L2,T,T2. ⦃G, L, T⦄ ≥[h, o] ⦃G2, L2, T2⦄ →
- ∀G1,L1,T1. ⦃G1, L1, T1⦄ >[h, o] ⦃G, L, T⦄ → ⦃G1, L1, T1⦄ >[h, o] ⦃G2, L2, T2⦄.
-#h #o #G #G2 #L #L2 #T #T2 #H @(fpbs_ind_dx … H) -G -L -T /3 width=5 by fpbg_fpbq_trans/
+lemma fpbg_intro (G3) (G4) (L3) (L4) (T3) (T4):
+ ∀G1,L1,T1,G2,L2,T2.
+ ❪G1,L1,T1❫ ≥ ❪G3,L3,T3❫ → ❪G3,L3,T3❫ ≻ ❪G4,L4,T4❫ →
+ ❪G4,L4,T4❫ ≥ ❪G2,L2,T2❫ → ❪G1,L1,T1❫ > ❪G2,L2,T2❫.
+/2 width=9 by ex3_6_intro/ qed.
+
+(* Basic_2A1: was: fpbg_fpbq_trans *)
+lemma fpbg_fpb_trans:
+ ∀G1,G,G2,L1,L,L2,T1,T,T2.
+ ❪G1,L1,T1❫ > ❪G,L,T❫ → ❪G,L,T❫ ≽ ❪G2,L2,T2❫ →
+ ❪G1,L1,T1❫ > ❪G2,L2,T2❫.
+#G1 #G #G2 #L1 #L #L2 #T1 #T #T2 #H1 #H2
+elim (fpbg_inv_gen … H1) -H1
+/3 width=13 by fpbs_strap1, fpbg_intro/