#
# This software is Copyright 2005 by Elsevier Inc.  You may use it
# under the terms of the license at http://perl.plover.com/hop/LICENSE.txt .
#



###
### factorial2
###

## Chapter 5 section 4.2

sub factorial {
  my ($n) = @_;
  my $product = 1;
  until ($n == 0) {
    $product *= $n;
    $n--;
  }
  return $product;
}