# Using @x and @y in this.
sub check
{
    my ($x, $y) = @_;

    return 0 unless $#$x == $#$y;

    for (0 .. $#$x)
    {
        return 0 if $x->[$_] ne $x->[$_] && $x->[$_] != $x->[$_];
    }

    return 1;
}