matitaB/matita/contribs/ng_assembly2/emulator/opcodes/byte_or_word.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 (* ********************************************************************** *)
  16 (*                          Progetto FreeScale                            *)
  17 (*                                                                        *)
  18 (*   Sviluppato da: Ing. Cosimo Oliboni, oliboni@cs.unibo.it              *)
  19 (*   Sviluppo: 2008-2010                                                  *)
  20 (*                                                                        *)
  21 (* ********************************************************************** *)
  22
  23 include "num/word16.ma".
  24
  25 (* raggruppamento di byte e word in un tipo unico *)
  26 ninductive byte8_or_word16 : Type ≝
  27   Byte: byte8  → byte8_or_word16
  28 | Word: word16 → byte8_or_word16.
  29
  30 ndefinition eq_b8w16 ≝
  31 λbw1,bw2:byte8_or_word16.
  32  match bw1 with
  33   [ Byte b1 ⇒ match bw2 with [ Byte b2 ⇒ eqc ? b1 b2 | Word _ ⇒ false ]
  34   | Word w1 ⇒ match bw2 with [ Byte _ ⇒ false | Word w2 ⇒ eqc ? w1 w2 ]
  35   ].