#include <bits/stdc++.h>
using  namespace  std;
using ll=long long;
int main(){
  int a,b,c,d;
  cin>>a>>b>>c>>d;
  if(abs(a-b)<=d&&abs(b-c)<=d||abs(a-c)<=d)cout<<"Yes"<<endl;
  else cout<<"No"<<endl;
}