import scala.io.StdIn._
import scala.math._
object Main extends App{
  val sc = new java.util.Scanner(System.in)
  val a,b ,c,d = sc.nextInt
  if(abs(c-a)<=d || (abs(b-a)<=d && abs(c-b)<=d)){
    print("Yes")
  }
  else{
    print("No")
  }
}