(* Forward lemmas with weight for terms *************************************)
(* Basic_2A1: includes: lift_fwd_tw *)
-lemma lifts_fwd_tw: ∀f,T1,T2. ⇧*[f] T1 ≘ T2 → ♯{T1} = ♯{T2}.
+lemma lifts_fwd_tw: ∀f,T1,T2. ⇧*[f] T1 ≘ T2 → ♯❨T1❩ = ♯❨T2❩.
#f #T1 #T2 #H elim H -f -T1 -T2 normalize //
qed-.