(* Properties with generic extension of a context sensitive relation ********)
-lemma rexs_lex (R): c_reflexive … R →
+lemma rexs_lex (R):
+ c_reflexive … R →
∀L1,L2,T. L1 ⪤[CTC … R] L2 → L1 ⪤*[R,T] L2.
#R #HR #L1 #L2 #T *
/5 width=7 by rexs_tc, sex_inv_tc_dx, sex_co, ext2_inv_tc, ext2_refl/
qed.
-lemma rexs_lex_req (R): c_reflexive … R →
+lemma rexs_lex_req (R):
+ c_reflexive … R →
∀L1,L. L1 ⪤[CTC … R] L → ∀L2,T. L ≡[T] L2 → L1 ⪤*[R,T] L2.
/3 width=3 by rexs_lex, rexs_step_dx, req_fwd_rex/ qed.
(* Note: s_rs_transitive_lex_inv_isid could be invoked in the last auto but makes it too slow *)
lemma rexs_inv_lex_req (R):
c_reflexive … R → rex_fsge_compatible R →
- s_rs_transitive … R (λ_.lex R) → req_transitive R →
+ s_rs_transitive … R (λ_.lex R) → R_transitive_req R →
∀L1,L2,T. L1 ⪤*[R,T] L2 →
∃∃L. L1 ⪤[CTC … R] L & L ≡[T] L2.
#R #H1R #H2R #H3R #H4R #L1 #L2 #T #H
[ /4 width=3 by req_refl, lex_refl, inj, ex2_intro/
| #L0 #L2 #_ #HL02 * #L * #f0 #Hf0 #HL1 #HL0
lapply (req_rex_trans … HL0 … HL02) -L0 // * #f1 #Hf1 #HL2
- elim (sex_sdj_split … ceq_ext … HL2 f0 ?) -HL2
+ elim (sex_sdj_split_sn … ceq_ext … HL2 f0 ?) -HL2
[ #L0 #HL0 #HL02 |*: /2 width=1 by ext2_refl, sdj_isid_dx/ ]
lapply (sex_sdj … HL0 f1 ?) /2 width=1 by sdj_isid_sn/ #H
elim (frees_sex_conf_fsge … Hf1 … H) // -H2R -H #f2 #Hf2 #Hf21