]> matita.cs.unibo.it Git - helm.git/blobdiff - matita/matita/contribs/lambdadelta/delayed_updating/etc/height/path_closed_height.etc
update in delayed_updating
[helm.git] / matita / matita / contribs / lambdadelta / delayed_updating / etc / height / path_closed_height.etc
index 88b0e413facd306e229f99ece950959fb4f04b72..72b6dead7f7c2a6c9b46a333f99c74a850c841d1 100644 (file)
@@ -18,10 +18,17 @@ include "delayed_updating/syntax/path_depth.ma".
 
 (* CLOSED CONDITION FOR PATH ************************************************)
 
-(* Constructions with height and depth **************************************)
+(* Destructions with height and depth ***************************************)
 
-lemma path_closed_depth (p) (n):
-      p ϵ 𝐂❨n❩ → ♯p + n = ♭p.
-#p #n #Hn elim Hn -Hn //
-#p #n #_ #IH <nplus_succ_dx //
-qed.
+lemma path_closed_des_depth (o) (q) (n):
+      q ϵ 𝐂❨o,n❩ → ♯q + n = ♭q.
+#o #q #n #Hq elim Hq -q -n //
+#q #n #_ #IH <nplus_succ_dx //
+qed-.
+
+lemma path_closed_des_succ_depth (o) (q) (n):
+      q ϵ 𝐂❨o,↑n❩ → ♭q = ↑↓♭q.
+#o #q #n #Hq
+<(path_closed_des_depth … Hq) -Hq
+<nplus_succ_dx <npred_succ //
+qed-.