#include <iostream>
#include <cmath>

using namespace std;

int main(){

  int a, b, c, d;

  while(cin >> a >> b >> c >> d){

    if((abs(a-b) <= d && abs(b-c)<= d)) cout << "YES" << endl;

    else if(abs(a-c)<=d) cout << "YES" << endl;

    else cout << "NO" << endl;

  }

  return 0;
}
