(* Main properties **********************************************************)
(* Basic_1: was: lift1_lift1 (left to right) *)
-theorem lifts_trans: ∀T1,T,des1. ⬆*[des1] T1 ≡ T → ∀T2:term. ∀des2. ⬆*[des2] T ≡ T2 →
- ⬆*[des1 @@ des2] T1 ≡ T2.
-#T1 #T #des1 #H elim H -T1 -T -des1 // /3 width=3/
+theorem lifts_trans: ∀T1,T,cs1. ⬆*[cs1] T1 ≡ T → ∀T2:term. ∀cs2. ⬆*[cs2] T ≡ T2 →
+ ⬆*[cs1 @@ cs2] T1 ≡ T2.
+#T1 #T #cs1 #H elim H -T1 -T -cs1 /3 width=3 by lifts_cons/
qed.