#include<bits/stdc++.h>
using namespace std;
int main()
{
  int a,b,c,d;
  cin>>a>>b>>c>>d;
  if(abs(a-c)<=d||(abs(a-b)<=d && abs(b-c)<=d))
  {
    cout<<"Yes";
  }
  else
    cout<<"No";
  return 0;
}