free a,b: bitstring [private].

channel c.

query attacker(a); attacker(b).


let P(x:bitstring)=
   sync 1 [S1];
   out(c,x).

process
    in(c, t: bool); if t then P(a) [sync: tag prefix T1] else P(b) [sync: tag prefix T1]

(* EXPECTPV
RESULT not attacker(a[]) is false.
RESULT not attacker(b[]) is false.
0.004s (user 0.004s + system 0.000s), max rss 7532K
END *)
