(* Basic forward lemmas *****************************************************)
-lemma tps_fwd_tw: ∀L,T1,T2,d,e. L ⊢ T1 ▶ [d, e] T2 → #{T1} ≤ #{T2}.
+lemma tps_fwd_tw: ∀L,T1,T2,d,e. L ⊢ T1 ▶ [d, e] T2 → ♯{T1} ≤ ♯{T2}.
#L #T1 #T2 #d #e #H elim H -L -T1 -T2 -d -e normalize
/3 by monotonic_le_plus_l, le_plus/ (**) (* just /3 width=1/ is too slow *)
qed-.