import java.util.Scanner;

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

    if(math.abs(a-c) <= d || (math.abs(a-b) <= d && math.abs(b-c) <= d))
      println("Yes");
    else
      println("No");
  }
}
