import java.util.Scanner

object Main {
  def main(args: Array[String]): Unit = {
    val sc = new Scanner(System.in)
    val a = sc.nextInt()
    val b = sc.nextInt()
    val c = sc.nextInt()
    val d = sc.nextInt()

    def abs(x: Int): Int = Math.abs(x)
    val ans = if ((abs(a - b) <= d && abs(b - c) <= d) || abs(a - c) <= d) {
      "Yes"
    } else {
      "No"
    }
    println(ans)
  }
}