#! /usr/bin/perl

        use Math::Matrix;

        $a = new Math::Matrix ([1], [2], [3]);
        $x = new Math::Matrix ([4], [5], [6]);

        $a->print("A\n");
        $x->print("X\n");

        $f = $a->cross_product( $x );
        print "output of a->cross_product( x ) is: '$f'\n\n";
        if( defined( $f ) ) { $f->print( "Cross product is \n" ) };

        $f = $a->cross_product( $a, $x );
        print "output of a->cross_product( a, x ) is: '$f'\n\n";
        if( defined( $f ) ) { $f->print( "Cross product is \n" ) };