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 include "ground/lib/subset_ext_equivalence.ma".
16 include "delayed_updating/unwind1/unwind_eq.ma".
17 include "delayed_updating/unwind1/unwind_prototerm.ma".
19 (* UNWIND FOR PROTOTERM *****************************************************)
21 (* Constructions with subset_equivalence ************************************)
23 lemma unwind_term_eq_repl_sn (f1) (f2) (t):
24 f1 ≗ f2 → ▼[f1]t ⇔ ▼[f2]t.
25 /3 width=1 by subset_equivalence_ext_f1_exteq, unwind_path_eq_repl/
28 lemma unwind_term_eq_repl_dx (f) (t1) (t2):
29 t1 ⇔ t2 → ▼[f]t1 ⇔ ▼[f]t2.
30 /2 width=1 by subset_equivalence_ext_f1_bi/
33 lemma unwind_term_after_id_sn (f) (t):
35 #f #t @subset_eq_trans
37 | @subset_inclusion_ext_f1_compose
38 | @subset_equivalence_ext_f1_exteq
39 #p @unwind_path_after_id_sn