+++ /dev/null
-(**************************************************************************)
-(* ___ *)
-(* ||M|| *)
-(* ||A|| A project by Andrea Asperti *)
-(* ||T|| *)
-(* ||I|| Developers: *)
-(* ||T|| The HELM team. *)
-(* ||A|| http://helm.cs.unibo.it *)
-(* \ / *)
-(* \ / This file is distributed under the terms of the *)
-(* v GNU General Public License Version 2 *)
-(* *)
-(**************************************************************************)
-
-include "ground_2/lib/star.ma".
-include "ground_2/lib/ltc.ma".
-
-(* LABELLED TRANSITIVE CLOSURE **********************************************)
-
-alias symbol "subseteq" = "relation inclusion".
-
-(* Properties with contextual transitive closure ****************************)
-
-lemma ltc_CTC (C) (A) (i) (f) (B) (R:relation4 C A B B):
- left_identity … f i →
- ∀c. CTC … (λc. R c i) c ⊆ ltc … f … (R c) i.
-#C #A #i #f #B #R #Hf #c #b1 #b2 #H elim H -b2 /2 width=1 by ltc_rc/
-#b #b2 #_ #Hb2 #IH >(Hf i) -Hf /2 width=3 by ltc_dx/
-qed.
-
-(* Inversion lemmas with contextual transitive closure **********************)
-
-lemma ltc_inv_CTC (C) (A) (i) (f) (B) (R:relation4 C A B B):
- associative … f → annulment_2 … f i →
- ∀c. ltc … f … (R c) i ⊆ CTC … (λc. R c i) c.
-#C #A #i #f #B #R #H1f #H2f #c #b1 #b2
-@(insert_eq_0 … i) #a #H
-@(ltc_ind_dx A f B … H) -a -b2 /2 width=1 by inj/ -H1f
-#a1 #a2 #b #b2 #_ #IH #Hb2 #H <H
-elim (H2f … H) -H2f -H #H1 #H2 destruct
-/3 width=3 by step/
-qed-.