X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=matita%2Fmatita%2Fcontribs%2Flambdadelta%2Fground_2%2Flib%2Fstreams_hdtl.ma;h=f128e5f73f8d4754566c0b1b6837c2b9b5835ffe;hb=a77d0bd6a04e94f765d329d47b37d9e04d349b14;hp=3a31efc350da7ba6e6769ce360969ddfa754b564;hpb=859c5cbb8ebffeddd1dd9cbc462e046b0709b4e4;p=helm.git

diff --git a/matita/matita/contribs/lambdadelta/ground_2/lib/streams_hdtl.ma b/matita/matita/contribs/lambdadelta/ground_2/lib/streams_hdtl.ma
index 3a31efc35..f128e5f73 100644
--- a/matita/matita/contribs/lambdadelta/ground_2/lib/streams_hdtl.ma
+++ b/matita/matita/contribs/lambdadelta/ground_2/lib/streams_hdtl.ma
@@ -12,7 +12,7 @@
 (*                                                                        *)
 (**************************************************************************)
 
-include "ground_2/notation/functions/drop_1.ma".
+include "ground_2/notation/functions/downspoon_2.ma".
 include "ground_2/lib/streams_eq.ma".
 include "ground_2/lib/arith.ma".
 
@@ -24,16 +24,16 @@ definition hd (A:Type[0]): stream A → A ≝
 definition tl (A:Type[0]): stream A → stream A ≝
               λt. match t with [ seq _ t ⇒ t ].
 
-interpretation "tail (streams)" 'Drop t = (tl ? t).
+interpretation "tail (streams)" 'DownSpoon A t = (tl A t).
 
 (* basic properties *********************************************************)
 
-lemma hd_rew (A) (a) (t): a = hd A (a@t).
+lemma hd_rew (A) (a) (t): a = hd A (a⨮t).
 // qed.
 
-lemma tl_rew (A) (a) (t): t = tl A (a@t).
+lemma tl_rew (A) (a) (t): t = tl A (a⨮t).
 // qed.
 
-lemma eq_stream_split (A) (t): (hd … t) @ ↓t ≐⦋A⦌ t.
+lemma eq_stream_split (A) (t): (hd … t) ⨮ ⫰t ≗{A} t.
 #A * //
 qed.