function main(input) {
	const args = input.split(' ');
	const a = parseInt(args[0], 10);
	const b = parseInt(args[1], 10);
	const c = parseInt(args[2], 10);
	const d = parseInt(args[3], 10);
	var t = 0;
	if(Math.abs(a-c)<=d){
		t = 1;
	} else if(Math.abs(a-b)<=d && Math.abs(b-c)<=d){
		t = 1;
	}
	if(t == 1){
		console.log('Yes');
	} else {
		console.log('No');
	}
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));