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