(* Title: HOLCF/IOA/ABP/Receiver.thy
ID: $Id$
Author: Olaf Müller
*)
header {* The implementation: receiver *}
theory Receiver
imports IOA Action Lemmas
begin
types
'm receiver_state = "'m list * bool" -- {* messages, mode *}
constdefs
rq :: "'m receiver_state => 'm list"
"rq == fst"
rbit :: "'m receiver_state => bool"
"rbit == snd"
receiver_asig :: "'m action signature"
"receiver_asig ==
(UN pkt. {R_pkt(pkt)},
(UN m. {R_msg(m)}) Un (UN b. {S_ack(b)}),
{})"
receiver_trans :: "('m action, 'm receiver_state)transition set"
"receiver_trans ==
{tr. let s = fst(tr);
t = snd(snd(tr))
in
case fst(snd(tr))
of
Next => False |
S_msg(m) => False |
R_msg(m) => (rq(s) ~= []) &
m = hd(rq(s)) &
rq(t) = tl(rq(s)) &
rbit(t)=rbit(s) |
S_pkt(pkt) => False |
R_pkt(pkt) => if (hdr(pkt) ~= rbit(s))&rq(s)=[] then
rq(t) = (rq(s)@[msg(pkt)]) &rbit(t) = (~rbit(s)) else
rq(t) =rq(s) & rbit(t)=rbit(s) |
S_ack(b) => b = rbit(s) &
rq(t) = rq(s) &
rbit(t)=rbit(s) |
R_ack(b) => False}"
receiver_ioa :: "('m action, 'm receiver_state)ioa"
"receiver_ioa ==
(receiver_asig, {([],False)}, receiver_trans,{},{})"
end