(* Title: HOLCF/IOA/ABP/Impl.thy ID: $Id: Env.thy,v 1.8 2007/10/21 12:21:50 wenzelm Exp $ Author: Olaf Müller *) header {* The environment *} theory Env imports IOA Action begin types 'm env_state = bool -- {* give next bit to system *} definition env_asig :: "'m action signature" where "env_asig == ({Next}, UN m. {S_msg(m)}, {})" definition env_trans :: "('m action, 'm env_state)transition set" where "env_trans = {tr. let s = fst(tr); t = snd(snd(tr)) in case fst(snd(tr)) of Next => t=True | S_msg(m) => s=True & t=False | R_msg(m) => False | S_pkt(pkt) => False | R_pkt(pkt) => False | S_ack(b) => False | R_ack(b) => False}" definition env_ioa :: "('m action, 'm env_state)ioa" where "env_ioa = (env_asig, {True}, env_trans,{},{})" axiomatization "next" :: "'m env_state => bool" end