(* Forward lemmas with length for local environments ************************)
(* Basic_2A1: includes: lreq_fwd_length *)
-lemma lreq_fwd_length: ∀L1,L2,f. L1 ≡[f] L2 → |L1| = |L2|.
+lemma lreq_fwd_length: ∀f,L1,L2. L1 ≡[f] L2 → |L1| = |L2|.
/2 width=4 by lexs_fwd_length/ qed-.