import std.stdio, std.conv, std.string, std.math, std.regex, std.range, std.ascii, std.algorithm;

void main(){
	auto N = readln.split.to!(int[]), a=N[0], b=N[1], c=N[2], d=N[3];
	if(abs(c-a)<=d||(abs(b-a)<=d&&abs(c-b)<=d)) writeln("Yes");
	else writeln("No");
}