#include <bits/stdc++.h>

using namespace std;

#define inf 1<<30
#define llong long long
#define usd unsigned
#define pqueue priority_queue
#define mp make_pair
#define pb push_back
#define fn fill_n
typedef pair<int, int> P;
int nw[9] = {0, 1, 0, -1, -1, 1, 1, -1, 0};
int nh[9] = {1, 0, -1, 0, 1, 1, -1, -1, 0};

int a, b, c, A[10000], B[10000], C[10000], e[100][100];
string s, t, r;


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