(* Advanced properties ******************************************************)
lemma sta_fpbg: ∀h,o,G,L,T1,T2,d. ⦃G, L⦄ ⊢ T1 ▪[h, o] d+1 →
- â¦\83G, Lâ¦\84 â\8a¢ T1 â\80¢*[h, 1] T2 â\86\92 â¦\83G, L, T1â¦\84 >â\89¡[h, o] ⦃G, L, T2⦄.
+ â¦\83G, Lâ¦\84 â\8a¢ T1 â\80¢*[h, 1] T2 â\86\92 â¦\83G, L, T1â¦\84 >â\89\9b[h, o] ⦃G, L, T2⦄.
/4 width=2 by fpb_fpbg, sta_fpb/ qed.