:- protocol(proto_hierarchyp,
extends(hierarchyp)).
:- info([
version is 1.0,
author is 'Paulo Moura',
date is 2000/7/24,
comment is 'Prototype hierarchy protocol.']).
:- public(parent/1).
:- mode(parent(?object), zero_or_more).
:- info(parent/1, [
comment is 'Returns, by backtracking, all object parents.',
argnames is ['Parent']]).
:- public(parents/1).
:- mode(parents(-list), one).
:- info(parents/1, [
comment is 'List of all object parents.',
argnames is ['Parents']]).
:- end_protocol.
