let hybrid sin_1_x () =
  let der t0 = 1.0 init 0.0 in
  let d = 0.6 in
  let t = t0 -. d in
  let der o = sin(1.0 /. t) *. (sin(1.0 /. t) -. (2.0 *. cos(1.0 /. t)) /. t)
			  init (-. d *. (sin(1.0 /. (-. d))) ** 2.0) in
  (present up(o) -> 1.0 else 0.0), o