]
qed-.
-lemma lfxs_inv_lref: â\88\80R,Y1,Y2,i. Y1 ⪤*[R, #⫯i] Y2 →
+lemma lfxs_inv_lref: â\88\80R,Y1,Y2,i. Y1 ⪤*[R, #â\86\91i] Y2 →
∨∨ Y1 = ⋆ ∧ Y2 = ⋆
| ∃∃I1,I2,L1,L2. L1 ⪤*[R, #i] L2 &
Y1 = L1.ⓘ{I1} & Y2 = L2.ⓘ{I2}.
]
qed-.
-lemma lfxs_inv_lref_bind_sn: â\88\80R,I1,K1,L2,i. K1.â\93\98{I1} ⪤*[R, #⫯i] L2 →
+lemma lfxs_inv_lref_bind_sn: â\88\80R,I1,K1,L2,i. K1.â\93\98{I1} ⪤*[R, #â\86\91i] L2 →
∃∃I2,K2. K1 ⪤*[R, #i] K2 & L2 = K2.ⓘ{I2}.
#R #I1 #K1 #L2 #i #H elim (lfxs_inv_lref … H) -H *
[ #H destruct
]
qed-.
-lemma lfxs_inv_lref_bind_dx: â\88\80R,I2,K2,L1,i. L1 ⪤*[R, #⫯i] K2.ⓘ{I2} →
+lemma lfxs_inv_lref_bind_dx: â\88\80R,I2,K2,L1,i. L1 ⪤*[R, #â\86\91i] K2.ⓘ{I2} →
∃∃I1,K1. K1 ⪤*[R, #i] K2 & L1 = K1.ⓘ{I1}.
#R #I2 #K2 #L1 #i #H elim (lfxs_inv_lref … H) -H *
[ #_ #H destruct
/4 width=3 by frees_unit, lexs_next, ext2_unit, ex2_intro/ qed.
lemma lfxs_lref: ∀R,I1,I2,L1,L2,i.
- L1 ⪤*[R, #i] L2 â\86\92 L1.â\93\98{I1} ⪤*[R, #⫯i] L2.ⓘ{I2}.
+ L1 ⪤*[R, #i] L2 â\86\92 L1.â\93\98{I1} ⪤*[R, #â\86\91i] L2.ⓘ{I2}.
#R #I1 #I2 #L1 #L2 #i * /3 width=3 by lexs_push, frees_lref, ex2_intro/
qed.