(* Title: HOL/IOA/ABP/Packet.thy ID: $Id$ Author: Tobias Nipkow & Olaf Mueller Copyright 1995 TU Muenchen Packets *) Packet = Arith + types 'msg packet = "bool * 'msg" consts hdr :: "'msg packet => bool" msg :: "'msg packet => 'msg" defs hdr_def "hdr == fst" msg_def "msg == snd" end