#include <bits/stdc++.h>
using namespace std;
 
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;
  }
}
