X-Git-Url: http://matita.cs.unibo.it/gitweb/?p=helm.git;a=blobdiff_plain;f=matita%2Fmatita%2Fcontribs%2Flambdadelta%2Fground_2%2Frelocation%2Fnstream_after.ma;h=6ce6fa476a68bc4e2ed4587653a9f4e0d25b2677;hp=0f21ba6c3774da6595e4df07715653c882f7f8d9;hb=053be41a8db6aa0ca7cc06fb569ec284a9bcc5ef;hpb=040c8158f327a3091c45295e91aaed2dedc137cb

diff --git a/matita/matita/contribs/lambdadelta/ground_2/relocation/nstream_after.ma b/matita/matita/contribs/lambdadelta/ground_2/relocation/nstream_after.ma
index 0f21ba6c3..6ce6fa476 100644
--- a/matita/matita/contribs/lambdadelta/ground_2/relocation/nstream_after.ma
+++ b/matita/matita/contribs/lambdadelta/ground_2/relocation/nstream_after.ma
@@ -151,3 +151,8 @@ qed-.
 lemma after_inv_apply: ∀f2,f1,f,n2,n1,n. n2⨮f2 ⊚ n1⨮f1 ≘ n⨮f →
                        (n2⨮f2)@❴n1❵ = n ∧ (⫰*[n1]f2) ⊚ f1 ≘ f.
 /3 width=3 by after_fwd_tls, after_fwd_hd, conj/ qed-.
+
+(* Properties on apply ******************************************************)
+
+lemma compose_apply (f2) (f1) (i): f2@❴f1@❴i❵❵ = (f2∘f1)@❴i❵.
+/4 width=6 by after_fwd_at, at_inv_total, sym_eq/ qed.