free c:channel.

fun h(bitstring):bitstring.

const a,b:bitstring.

event A(bitstring).

const ok,ko:bitstring.

lemma x:bitstring,y:bitstring; event(A(x)) ==> x=b.


query x:bitstring; event(A(x)).

process
  in(c,x:bitstring);
  if x = a
  then
    event A(a);
    out(c,ok)
  else
    out(c,ko)

(* EXPECTPV
RESULT event(A(x_1)) ==> x_1 = b is false.
0.008s (user 0.008s + system 0.000s), max rss 7292K
END *)
