'use strict';

function Main(input) {
  const list = input.split(' ');
  let dis_a_c = Math.abs(Number(list[2]) - Number(list[0]));
  let dis_a_b = Math.abs(Number(list[1]) - Number(list[0]));
  let dis_b_c = Math.abs(Number(list[2]) - Number(list[1]));
  let okdis = Number(list[3]);

  if(dis_a_c <= okdis) {
    console.log('Yes')
  }
  else if(dis_a_b <= okdis && dis_b_c <= okdis) {
    console.log('Yes');
  }
  else {
    console.log('No');
  }
  
}
 
Main(require("fs").readFileSync("/dev/stdin", "utf8"));