matita/matita/contribs/lambdadelta/alpha_1/syntax/term_append.ma

   1 (**************************************************************************)
   2 (*       ___                                                              *)
   3 (*      ||M||                                                             *)
   4 (*      ||A||       A project by Andrea Asperti                           *)
   5 (*      ||T||                                                             *)
   6 (*      ||I||       Developers:                                           *)
   7 (*      ||T||         The HELM team.                                      *)
   8 (*      ||A||         http://helm.cs.unibo.it                             *)
   9 (*      \   /                                                             *)
  10 (*       \ /        This file is distributed under the terms of the       *)
  11 (*        v         GNU General Public License Version 2                  *)
  12 (*                                                                        *)
  13 (**************************************************************************)
  14
  15 include "alpha_1/syntax/term.ma".
  16
  17 (* TERMS ********************************************************************)
  18
  19 let rec tappend T U on T ≝ match T with
  20 [ TAtom       ⇒ U
  21 | TUnit I T   ⇒ ①[I].(tappend T U)
  22 | TPair I V T ⇒ ②[I]V.(tappend T U)
  23 ].
  24
  25 interpretation "append (term)" 'plus T U = (tappend T U).