type nonce.

fun hash(nonce): nonce.

nounif x:sid; attacker(choice[new n[!1 = x], hash(new n[!1 = x])]).
nounif attacker(new n).
(* nounif x: sid, y: sid; attacker(new n[!1 = choice[x,y]]).*)

free c: channel.

process !
	new n: nonce;
	out(c, choice[n, hash(n)])

(* EXPECTPV
RESULT Observational equivalence is true.
0.008s (user 0.004s + system 0.004s), max rss 8672K
END *)
