:- protocol(abstract_classp).
:- info([
version is 1.0,
author is 'Paulo Moura',
date is 2000/7/24,
comment is 'Default protocol for all abstract classes.']).
:- public(metaclass/0).
:- mode(metaclass, zero_or_one).
:- info(metaclass/0, [
comment is 'True if the object is a metaclass.']).
:- public(abstract_class/0).
:- mode(abstract_class, zero_or_one).
comment is 'True if the object is an abstract class.']).
:- end_protocol.
