free c:channel.
free d:channel [private].

fun h(bitstring):bitstring.

const a,b:bitstring.

event A(bitstring).
event B(bitstring).

const ok,ko,k:bitstring[private].

axiom x:bitstring,y:bitstring; event(A(x)) ==> x <> a [fullSat].


process
  (in(c,(x:bitstring,y:bitstring));
   event B(x);
   event A(y);
   out(d,x))
  | in(d,x:bitstring); if x = a then out(c,choice[a,b])

(* EXPECTPV
RESULT Observational equivalence cannot be proved.
0.032s (user 0.012s + system 0.020s), max rss 8900K
END *)
