#h #g #R #IH #G #L #T #H @(csx_ind_fpbu … H) -G -L -T
#G1 #L1 #T1 #H1 #IH1 #A1 #HTA1 @IH -IH //
#G2 #L2 #T2 #H12 elim (fpbs_aaa_conf h g … G2 … L2 … T2 … HTA1) -A1
-/2 width=2 by fpbu_fpbs/
+/2 width=2 by fpb_fpbs/
qed-.
lemma aaa_ind_fpbu: ∀h,g. ∀R:relation3 genv lenv term.