let () =
  let a,b,c,d = Scanf.scanf "%d %d %d %d " (fun a b c d -> a,b,c,d) in
  print_endline (
    if (abs(c - a) <= d) then "Yes" else
    if (abs(c - b) <= d) && (abs(b - a) <= d) then "Yes" else "No"
  )
