(* *)
(**************************************************************************)
+include "basic_2/computation/lpxs_lpxs.ma".
include "basic_2/computation/fpbs_alt.ma".
include "basic_2/computation/fpbg.ma".
lemma fpbg_fwd_fpbs: ∀h,g,G1,G2,L1,L2,T1,T2. ⦃G1, L1, T1⦄ >[h, g] ⦃G2, L2, T2⦄ →
⦃G1, L1, T1⦄ ≥[h, g] ⦃G2, L2, T2⦄.
#h #g #G1 #G2 #L1 #L2 #T1 #T2 #H elim H -G2 -L2 -T2
-/3 width=5 by cpxs_fqup_fpbs, fpbs_trans, lpxs_fpbs, cpxs_fpbs/
+/3 width=5 by cpxs_fqus_lpxs_fpbs, cpxs_fqup_fpbs, fpbs_trans, lpxs_fpbs, cpxs_fpbs/
qed-.
-lemma fpbg_fwd_fpb_sn: ∀h,g,G1,G2,L1,L2,T1,T2. ⦃G1, L1, T1⦄ >[h, g] ⦃G2, L2, T2⦄ →
- ∃∃G,L,T. ⦃G1, L1, T1⦄ ≻[h, g] ⦃G, L, T⦄ & ⦃G, L, T⦄ ≥[h, g] ⦃G2, L2, T2⦄.
+lemma fpbg_fwd_fpbc_sn: ∀h,g,G1,G2,L1,L2,T1,T2. ⦃G1, L1, T1⦄ >[h, g] ⦃G2, L2, T2⦄ →
+ ∃∃G,L,T. ⦃G1, L1, T1⦄ ≻[h, g] ⦃G, L, T⦄ & ⦃G, L, T⦄ ≥[h, g] ⦃G2, L2, T2⦄.
#h #g #G1 #G2 #L1 #L2 #T1 #T2 #H elim H -G2 -L2 -T2
-[ #L2 #T2 #HT12 #H #HL12
- elim (cpxs_neq_inv_step_sn … HT12 H) -HT12 -H
- /4 width=9 by fpbsa_inv_fpbs, fpbc_cpx, ex3_2_intro, ex2_3_intro/
+[ /4 width=5 by fpbc_cpxs, lpxs_fpbs, ex2_3_intro/
| #G2 #L #L2 #T #T2 #HT1 #HT2 #HL2 elim (eq_term_dec T1 T) #H destruct
- [ -HT1 elim (fqup_inv_step_sn … HT2) -HT2
- /4 width=9 by fpbsa_inv_fpbs, fpbc_fqu, ex3_2_intro, ex2_3_intro/
- | elim (cpxs_neq_inv_step_sn … HT1 H) -HT1 -H
- /5 width=9 by fpbsa_inv_fpbs, fpbc_cpx, fqup_fqus, ex3_2_intro, ex2_3_intro/
+ [ -HT1 /3 width=5 by fpbc_fqup, lpxs_fpbs, ex2_3_intro/
+ | /5 width=9 by fpbc_cpxs, fpbsa_inv_fpbs, fqup_fqus, ex3_2_intro, ex2_3_intro/
+ ]
+| #G2 #L #L0 #L2 #T #T2 #HT1 #HT2 #HL0 #H0 #HL02 #H02
+ lapply (lpxs_trans … HL0 … HL02) #HL2
+ elim (eq_term_dec T1 T) #H destruct
+ [ -HT1 elim (fqus_inv_gen … HT2) -HT2
+ [ /3 width=5 by fpbc_fqup, lpxs_fpbs, ex2_3_intro/
+ | * #H1 #H2 #H3 destruct
+ /4 width=5 by fpbc_lpxs, lpxs_fpbs, ex2_3_intro/
+ ]
+ | /4 width=9 by fpbc_cpxs, fpbsa_inv_fpbs, ex3_2_intro, ex2_3_intro/
]
]
qed-.