#include<iostream>
#include<cstdio>
#include<string.h>
#include<algorithm>
#include<cmath>
using namespace std;
int a,b,c,d;

int main()
{
    cin>>a>>b>>c>>d;
        if (abs(c-a)<=d || abs(a-b)<=d && abs(b-c)<=d)
        {
            cout<<"Yes"<<endl;
        }else cout<<"No"<<endl;
    return 0;
}

