(* Basic_2A1: uses: lleq_inv_lift_le lleq_inv_lift_be lleq_inv_lift_ge *)
lemma req_inv_lifts_bi: ∀L1,L2,U. L1 ≡[U] L2 → ∀b,f. 𝐔⦃f⦄ →
- â\88\80K1,K2. â¬\87*[b,f] L1 â\89\98 K1 â\86\92 â¬\87*[b,f] L2 ≘ K2 →
- â\88\80T. â¬\86*[f] T ≘ U → K1 ≡[T] K2.
+ â\88\80K1,K2. â\87©*[b,f] L1 â\89\98 K1 â\86\92 â\87©*[b,f] L2 ≘ K2 →
+ â\88\80T. â\87§*[f] T ≘ U → K1 ≡[T] K2.
/2 width=10 by rex_inv_lifts_bi/ qed-.