free pub: channel.

free c0: bitstring.

event A.

restriction attacker(c0) ==> false.

query event(A) ==> false.

(* The restriction is false on all traces, because c0 is public.
   So it is impossible to find an attack against the query that 
   satisfies the restriction. *)

process
   event A

(* EXPECTPV
RESULT not event(A) cannot be proved.
0.032s (user 0.008s + system 0.024s), max rss 8560K
END *)
