sub member {
    my ($target, @list) = @_;
    Carp::croak "No target in member/2 " if ! @list;
    if (defined $target) {
        for (0 .. $#list) {
            return $_ if $list[$_] eq $target;
        }
        return $NEG;
    }
    else {
        for (0 .. $#item) {
            return $_ if ! defined $item[$_];
        }
        return $NEG;
    }
}