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4 (* ||A|| A project by Andrea Asperti *)
6 (* ||I|| Developers: *)
7 (* ||T|| The HELM team. *)
8 (* ||A|| http://helm.cs.unibo.it *)
10 (* \ / This file is distributed under the terms of the *)
11 (* v GNU General Public License Version 2 *)
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15 include "delayed_updating/substitution/lift_path.ma".
16 include "ground/lib/list_length.ma".
18 (* LIFT FOR PATH ************************************************************)
20 (* Constructions with list_length *******************************************)
22 lemma lift_path_length (f) (p):
23 āpā = āš ”[f]pā.
24 #f #p elim p -p // * [ #k ] #p #IH
31 >list_length_lcons >list_length_lcons //