function Main(input) {
  input = input.trim()
  input = input.split(" ").map(Number);
  if(Math.abs(input[0]-input[2])<=input[3]||(Math.abs(input[0]-input[1])<=input[3]&&Math.abs(input[1]-input[2])<=input[3]))　console.log("Yes");
  else console.log("No")
}Main(require("fs").readFileSync("/dev/stdin", "utf8"));