function Main(input) {
    tmp = input.split(" ");
    var a = parseInt(tmp[0], 10);
    var b = parseInt(tmp[1], 10);
    var c = parseInt(tmp[2], 10);
    var d = parseInt(tmp[3], 10);
    var z;
    //計算
        //直接
    var e = a-c;
        //間接
    var f = a-b;
    var g = b-c;
    //if
    if (e <= d || f <= d && g <= d) {
        z = "Yes";
    } else {
        z = "No";
    }
    //結果
    console.log(z);
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));