This is a good point, and may be an argument for having a "formal_maybe" or perhaps having it check at least as many arguments as there are formal arguments. Ho

This is a good point, and may be an argument for having a "formal_maybe" or perhaps having it check at least as many arguments as there are formal arguments. However, I don't think that this situation would be as important in practical use. You would normally use this function to allow for passed arguments to be null or undefined - not to allow for some arguments not to be passed.