node f_xor(a,b:bool) = (c:bool)
let
   c = (a and not b) or (not a and b);
tel

(* CHECK main *)
node main() returns (ok:bool)
  var x, y, z : bool;
let
    z = x xor y;
  x = false fby false fby true;
  y = false fby true fby false fby true;
  ok = (z = f_xor(x,y));
tel
