import java.util.Scanner

object Main {
  def main(args: Array[String]): Unit = println(solve(new Scanner(System.in)))

  def solve(in: String): String = solve(new Scanner(in))

  def solve(sc: Scanner): String = {
    val a = sc.nextInt
    val b = sc.nextInt
    val c = sc.nextInt
    val d = sc.nextInt

    if (Math.abs(a - c) <= d || (Math.abs(a - b) <= d && Math.abs(b - c) <= d)) {
      "Yes"
    } else {
      "No"
    }
  }
}
