(function js(){
	var a,
	    b,
	    c,
	    d,
	    line;
	line = readline().split(" ");
	a = line[0];
	b = line[1];
	c = line[2];
	d = line[3];
	//c-a
	var ac = Math.abs(a-c);
	var ab = Math.abs(a-b);
	var bc = Math.abs(b-c);
	var flag=false;
	if(ac<=d){
		flag=true;
	}else if(ab<=d&&bc<=d){
		flag=true;
	}
	if(flag){
		print('Yes');
	}else{
		print('No');
	}
	
})();
