function main(input) {
  const tmp = input.trim().split(' ').map((n) => parseInt(n, 10))
  const a = tmp[0]
  const b = tmp[1]
  const c = tmp[2]
  const d = tmp[3]

  if (Math.abs(a - c) <= d || (Math.abs(a - b) <= d && Math.abs(b - c) <= d)) {
    console.log('Yes')
  } else {
    console.log('No')
  }
}

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