public class Main {
	public static void main(String[] args) {
		Knoten n17 = new Zahl(17);
		Knoten n4 = new Zahl(4);
		Knoten add = new Add(n17,n4);
		Knoten n2 = new Zahl(2);
		Knoten mult = new Mult(add,n2);
		
		//objektorientiert
		System.out.println(mult.rechne());

		//dispatch per instanceof
		System.out.println(new Rechne().rechne(mult));

		//visitor pattern
		Rechne2 r2 = new Rechne2();
		mult.welcome(r2);
		System.out.println(r2.result);
	}
}