1 (**************************************************************************)
4 (* ||A|| A project by Andrea Asperti *)
6 (* ||I|| Developers: *)
7 (* ||T|| The HELM team. *)
8 (* ||A|| http://helm.cs.unibo.it *)
10 (* \ / This file is distributed under the terms of the *)
11 (* v GNU General Public License Version 2 *)
13 (**************************************************************************)
15 include "ground/notation/functions/downharpoonleft_2.ma".
16 include "ground/notation/functions/downharpoonright_2.ma".
17 include "ground/lib/stream.ma".
19 (* HEAD AND TAIL FOR STREAMS ************************************************)
21 definition stream_hd (A:Type[0]): stream A → A.
27 'DownHarpoonLeft A t = (stream_hd A t).
29 definition stream_tl (A:Type[0]): stream A → stream A.
35 'DownHarpoonRight A t = (stream_tl A t).
37 (* Basic constructions ******************************************************)
39 lemma stream_hd_cons (A) (a) (t):
43 lemma stream_tl_cons (A) (a) (t):
47 lemma stream_split_tl (A) (t):