function Main(input){
	input1 = input.split(' ');
    input2 = input1.map(input1=>parseInt(input1,10));
    a = input2[0];
    b = input2[1];
    c = input2[2];
    d = input2[3];
    ans = ''
    if(Math.abs(a-b <=d)){
    ans = 1;
    }else if(Math.abs(a-b <=d) && Math.abs(b-c <=d)){
    ans = 1;
    }else{
    ans = 0;
    }
    if(ans == 1){
    console.log('Yes');
    }else if(ans == 0){
    console.log('No');
    }
}
Main(require("fs").readFileSync("/dev/stdin","utf8"));