- uniform relocations

[helm.git] / matita / matita / contribs / lambdadelta / ground_2 / relocation / rtmap_at.ma

diff --git a/matita/matita/contribs/lambdadelta/ground_2/relocation/rtmap_at.ma b/matita/matita/contribs/lambdadelta/ground_2/relocation/rtmap_at.ma
index 00ee4edb2d5c0d2d9e37bcc54e2975af503e2422..06223bc534baba0a840088c7471c56d3733b719f 100644 (file)
--- a/matita/matita/contribs/lambdadelta/ground_2/relocation/rtmap_at.ma
+++ b/matita/matita/contribs/lambdadelta/ground_2/relocation/rtmap_at.ma
@@ -183,7 +183,7 @@ qed-.
 
 (* Basic properties *********************************************************)
 
-let corec at_eq_repl_back: ∀i1,i2. eq_repl_back (λf. @⦃i1, f⦄ ≡ i2) ≝ ?.
+corec lemma at_eq_repl_back: ∀i1,i2. eq_repl_back (λf. @⦃i1, f⦄ ≡ i2).
 #i1 #i2 #f1 #H1 cases H1 -f1 -i1 -i2
 [ #f1 #g1 #j1 #j2 #H #H1 #H2 #f2 #H12 cases (eq_inv_px … H12 … H) -g1 /2 width=2 by at_refl/
 | #f1 #i1 #i2 #Hf1 #g1 #j1 #j2 #H #H1 #H2 #f2 #H12 cases (eq_inv_px … H12 … H) -g1 /3 width=7 by at_push/
@@ -274,6 +274,25 @@ lemma at_pxx_tls: ∀n,f. @⦃0, f⦄ ≡ n → @⦃0, ⫱*[n]f⦄ ≡ 0.
 #n #IH #f #Hf cases (at_inv_pxn … Hf) -Hf /2 width=3 by/
 qed.
 
+lemma at_tls: ∀i2,f. ↑⫱*[⫯i2]f ≗ ⫱*[i2]f → ∃i1. @⦃i1, f⦄ ≡ i2.
+#i2 elim i2 -i2
+[ /4 width=4 by at_eq_repl_back, at_refl, ex_intro/
+| #i2 #IH #f <tls_xn <tls_xn in ⊢ (??%→?); #H
+  elim (IH … H) -IH -H #i1 #Hf
+  elim (pn_split f) * #g #Hg destruct /3 width=8 by at_push, at_next, ex_intro/  
+]
+qed-.
+
+(* Inversion lemmas with tls ************************************************)
+
+lemma at_inv_tls: ∀i2,i1,f. @⦃i1, f⦄ ≡ i2 → ↑⫱*[⫯i2]f ≗ ⫱*[i2]f.
+#i2 elim i2 -i2
+[ #i1 #f #Hf elim (at_inv_xxp … Hf) -Hf // #g #H1 #H destruct
+  /2 width=1 by eq_refl/
+| #i2 #IH #i1 #f #Hf elim (at_inv_xxn … Hf) -Hf [1,3: * |*: // ] /2 width=2 by/
+]
+qed-.
+
 (* Advanced inversion lemmas on isid ****************************************)
 
 lemma isid_inv_at: ∀i,f. 𝐈⦃f⦄ → @⦃i, f⦄ ≡ i.
@@ -286,9 +305,9 @@ qed.
 lemma isid_inv_at_mono: ∀f,i1,i2. 𝐈⦃f⦄ → @⦃i1, f⦄ ≡ i2 → i1 = i2.
 /3 width=6 by isid_inv_at, at_mono/ qed-.
 
-(* Advancedd properties on isid *********************************************)
+(* Advanced properties on isid **********************************************)
 
-let corec isid_at: ∀f. (∀i. @⦃i, f⦄ ≡ i) → 𝐈⦃f⦄ ≝ ?.
+corec lemma isid_at: ∀f. (∀i. @⦃i, f⦄ ≡ i) → 𝐈⦃f⦄.
 #f #Hf lapply (Hf 0)
 #H cases (at_fwd_id_ex … H) -H
 #g #H @(isid_push … H) /3 width=7 by at_inv_npn/