#include<iostream>
#include <stdio.h>
#include<algorithm>
#include<string.h>
#include<cmath>
#include <vector>
using namespace std;
int main()
{
    int a,b,c,d;
    scanf("%d%d%d%d",&a,&b,&c,&d);
    if(abs(a-c)<=d)printf("Yes");
    else if(abs(a-b)<=d&&abs(b-c)<=d)printf("Yes");
    else printf("No");
}


