#include<iostream>
#include<cstdio>
#include<cstring>
#include<string>
#include<cstdlib>
#include<vector>
#include<queue>
#include<algorithm>
#include<cmath>
using namespace std;
typedef long long ll;
typedef pair<int, int>pii;
const int N = 1e6+5;
int ABS(int a)
{
    if(a < 0) return -a;
    return a;
}
int main()
{
    int a, b, c, d;
    scanf("%d%d%d%d", &a, &b, &c, &d);
    if(ABS(a-c) <= d)
    {
        printf("Yes\n");
    }
    else
    {
        if(ABS(a-b)<=d && ABS(b-c)<=d)
            printf("Yes\n");
        else printf("No\n");
    }
}
