function Main(input) {
    var abcd = input.split('/n')[0].split(' ');
    var a = parseInt(abcd[0], 10);
    var b = parseInt(abcd[1], 10);
    var c = parseInt(abcd[2], 10);
    var d = parseInt(abcd[3], 10);
    
    if (Math.abs(c-a) <= d || (Math.abs(c-b) <= d && Math.abs(b-a) <= d)) {
        console.log('Yes');
    } else {
        console.log('No');
    }
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));