#include<iostream>
#include<algorithm>
using namespace std;

int main(){
    int a,b,c,d,e,f,g;
    cin>>a>>b>>c>>d;
    if(a>=c){
        e=a-c;
        if(b>a){
            g=d+1;
            f=d+1;
        }
        else{
            g=a-b;
            f=b-c;
        }

    }
    else{
        e=c-a;
        if(b>c){
            g=d+1;
            f=d+1;
        }
        else{
            g=b-a;
            f=c-b;
        }
    }
    if(e<=d)
        cout<<"Yes"<<endl;
    else if(f<=d&&g<=d)
        cout<<"Yes"<<endl;
    else
        cout<<"No"<<endl;
    return 0;
}
