(* Note: req_inv_lifts_dx missing in basic_2A1 *)
(* Basic_2A1: uses: lleq_inv_lift_le lleq_inv_lift_be lleq_inv_lift_ge *)
-lemma req_inv_lifts_bi: â\88\80L1,L2,U. L1 â\89¡[U] L2 â\86\92 â\88\80b,f. ð\9d\90\94â¦\83fâ¦\84 →
+lemma req_inv_lifts_bi: â\88\80L1,L2,U. L1 â\89¡[U] L2 â\86\92 â\88\80b,f. ð\9d\90\94â\9dªfâ\9d« →
∀K1,K2. ⇩*[b,f] L1 ≘ K1 → ⇩*[b,f] L2 ≘ K2 →
∀T. ⇧*[f] T ≘ U → K1 ≡[T] K2.
/2 width=10 by rex_inv_lifts_bi/ qed-.