-(* Note: missing in basic_2A1 *)
-lemma lfdeq_inv_lifts_bi: â\88\80h,o,L1,L2,U. L1 â\89¡[h, o, U] L2 →
- ∀K1,K2,i. ⬇*[i] L1 ≡ K1 → ⬇*[i] L2 ≡ K2 →
- ∀T. ⬆*[i] T ≡ U → K1 ≡[h, o, T] K2.
-/2 width=8 by lfxs_inv_lifts_bi/ qed-.
+(* Basic_2A1: uses: lleq_inv_lift_le lleq_inv_lift_be lleq_inv_lift_ge *)
+lemma lfdeq_inv_lifts_bi: â\88\80h,o,L1,L2,U. L1 â\89\9b[h, o, U] L2 â\86\92 â\88\80b,f. ð\9d\90\94â¦\83fâ¦\84 →
+ ∀K1,K2. ⬇*[b, f] L1 ≘ K1 → ⬇*[b, f] L2 ≘ K2 →
+ ∀T. ⬆*[f] T ≘ U → K1 ≛[h, o, T] K2.
+/2 width=10 by lfxs_inv_lifts_bi/ qed-.