free c0: bitstring [private].
free c1: bitstring.

restriction attacker(c0) ==> false.

channel c.

equivalence
	in(c, x: bitstring); out(c, c0)

	in(c, x: bitstring); out(c, c1)

(* EXPECTPV
Error: Restrictions are not allowed when ProVerif proves the equivalence of two processes.
xtime: error in child process (status : 2)
END *)
