1 (**************************************************************************)
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 *)
13 (**************************************************************************)
15 (**) (* reverse include *)
16 include "ground/lib/subset_ext_equivalence.ma".
17 include "delayed_updating/substitution/lift_prototerm.ma".
18 include "delayed_updating/unwind/unwind2_path_lift.ma".
19 include "delayed_updating/unwind/unwind2_prototerm.ma".
21 (* UNWIND FOR PROTOTERM *****************************************************)
23 (* Constructions with lift_prototerm ****************************************)
25 lemma lift_unwind2_term_after (f1) (f2) (t):
26 ↑[f2]▼[f1]t ⇔ ▼[f2∘f1]t.
27 #f1 #f2 #t @subset_eq_trans
28 [| @subset_inclusion_ext_f1_compose ]
29 @subset_equivalence_ext_f1_exteq #p
30 @lift_unwind2_path_after
33 lemma unwind2_term_after_lift (f1) (f2) (t):
34 ▼[f2]↑[f1]t ⇔ ▼[f2∘f1]t.
35 #f1 #f2 #t @subset_eq_trans
36 [| @subset_inclusion_ext_f1_compose ]
37 @subset_equivalence_ext_f1_exteq #p
38 @unwind2_path_after_lift