'use strict'

function main(s) {

  s = s.split('\n')[0].split(' ').map(x => Number(x));
  const a = s[0];
  const b = s[1];
  const c = s[2];
  const d = s[3];
  const indirect = (Math.abs(b - a) <= d && Math.abs(c - b) <= d);
  const direct = (Math.abs(c - a) <= d);
  const ans = (indirect || direct) ? 'Yes' : 'No';

  console.log(ans);
}

main(require("fs").readFileSync("/dev/stdin", "utf8"));
