Implementierung

• public class Li<a>{
    private a hd;
    private Li<a> tl;
    private boolean empty=false;
  
    public Li(){empty=true;}
    public Li(a h,Li<a> t){hd=h;tl=l;}
    public a head(){return hd;} 
    public Li<a> head(){return tl;} 
    public boolean isEmpty(){return empty;}
  }