free a,b,c,ok:bitstring.
channel io.

table tbl(bitstring,bitstring).

free x:bitstring[private].
noninterf x among (a,b).

process
  (* let x = diff[a,b] in *)

  (
    get tbl(=x,k) in
    out(io,ok)
  ) |
  ! in(io,o:bitstring);
    if o <> a then
    new k:bitstring;
    insert tbl(o,k)

(* EXPECTPV
RESULT Non-interference x among (a[], b[]) cannot be proved.
0.012s (user 0.004s + system 0.008s), max rss 8484K
END *)
