if (0) { # perform some random tests on the Zeckendorf class. disabled by default because slow.
	for my $i (1 .. 100) {
		my $m = int rand(1e7);
		my $x = Zeckendorf->fromnat($m);
		$m == $x->val or die;
		my $n = int rand(1e7);
		my $y = Zeckendorf->fromnat($n);
		$n == $y->val or die;
		my $s = $m + $n;
		my $z = $x->add($y);
		$s == $z->val or die;
	}
}