function Main(input){
	input1 = input.trim().split(' ').map(v=>parseInt(v,10));
    a = input1[0];
    b = input1[1];
    c = input1[2];
    d = input1[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"));