X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=matita%2Fmatita%2Fcontribs%2Flambdadelta%2Fground%2Flib%2Fstream_hdtl.ma;h=a23cb4ca8caab2ef31e6eeb7598ead4986d5cf10;hb=dc605ae41c39773f55381f241b1ed3db4acf5edd;hp=4a3640baed498488974f0c6e34ec370343c8d807;hpb=6604a232815858a6c75dd25ac45abd68438077ff;p=helm.git

diff --git a/matita/matita/contribs/lambdadelta/ground/lib/stream_hdtl.ma b/matita/matita/contribs/lambdadelta/ground/lib/stream_hdtl.ma
index 4a3640bae..a23cb4ca8 100644
--- a/matita/matita/contribs/lambdadelta/ground/lib/stream_hdtl.ma
+++ b/matita/matita/contribs/lambdadelta/ground/lib/stream_hdtl.ma
@@ -12,20 +12,22 @@
 (*                                                                        *)
 (**************************************************************************)
 
-include "ground/notation/functions/downspoon_2.ma".
-include "ground/lib/stream_eq.ma".
+include "ground/notation/functions/downdashedarrow_2.ma".
+include "ground/lib/stream.ma".
 
 (* HEAD AND TAIL FOR STREAMS ************************************************)
 
-definition stream_hd (A:Type[0]): stream A → A ≝
-           λt. match t with [ stream_cons a _ ⇒ a ].
+definition stream_hd (A:Type[0]): stream A → A.
+#A * #a #_ @a
+defined.
 
-definition stream_tl (A:Type[0]): stream A → stream A ≝
-           λt. match t with [ stream_cons _ t ⇒ t ].
+definition stream_tl (A:Type[0]): stream A → stream A.
+#A * #_ #t @t
+defined.
 
 interpretation
   "tail (streams)"
-  'DownSpoon A t = (stream_tl A t).
+  'DownDashedArrow A t = (stream_tl A t).
 
 (* Basic constructions ******************************************************)
 
@@ -34,10 +36,10 @@ lemma stream_hd_cons (A) (a) (t):
 // qed.
 
 lemma stream_tl_cons (A) (a) (t):
-      t = ⫰{A}(a⨮t).
+      t = ⇣{A}(a⨮t).
 // qed.
 
-lemma eq_stream_split_hd_tl (A) (t):
-      stream_hd … t ⨮ ⫰t ≗{A} t.
+lemma stream_split_tl (A) (t):
+      stream_hd A t ⨮ ⇣t = t.
 #A * //
 qed.