package api;

 /** Class showing inventive, non-expected use of 

  * Arithmetica methods to do multiplication instead of

  * addition.

  */

 //BEGIN: design.composition.arith.factorial

 public final class Factorial extends Arithmetica {

     public static int factorial(int n) {

         return new Factorial().sumRange(1, n);

     }

     @Override

     public int sumTwo(int one, int second) {

         return one * second;

     }

 }

 //END: design.composition.arith.factorial