update in delayed_updating

[helm.git] / matita / matita / contribs / lambdadelta / delayed_updating / syntax / path_reverse.ma

diff --git a/matita/matita/contribs/lambdadelta/delayed_updating/syntax/path_reverse.ma b/matita/matita/contribs/lambdadelta/delayed_updating/syntax/path_reverse.ma
index 43d9d85e8cc87de808c7b1f26ae1e57430146c38..046404f0375e4b32f626794cb2c0e81b243000e4 100644 (file)
--- a/matita/matita/contribs/lambdadelta/delayed_updating/syntax/path_reverse.ma
+++ b/matita/matita/contribs/lambdadelta/delayed_updating/syntax/path_reverse.ma
@@ -51,3 +51,12 @@ lemma reverse_rcons (p) (l):
 #p #l
 <reverse_append //
 qed.
+
+(* Main constructions *******************************************************)
+
+theorem reverse_revrse (p):
+        p = pᴿᴿ.
+#p elim p -p //
+#l #p #IH
+<reverse_lcons <reverse_rcons //
+qed.