Algernon Tutorial 2.d
Macros involving classes and instances

previous next

These exercises and examples use the newspaper project included in the examples folder of your Protege installation.

Except for :CHILD and :PARENT, all of the commands discussed on his page will work in two modes. If the clause is ground, it verifies that the given relationship exists in the KB. If the clause is not ground, it retrieves data from the KB. They can not be used to assert information into the KB.

:CHILD and :PARENT

:CHILD and :PARENT compare two frames across the class abstraction hierarchy without regard to whether the arguments are classes or instances.

((:CHILD :THING Author))
((:FAIL (:CHILD Author :THING)))
((:FAIL (:PARENT :THING Author)))
((:PARENT Author :THING))

:SUBCLASS, :SUPERCLASS and :CLASS, :INSTANCE

These return all subclasses or superclasses of a class (not just direct subclasses or superclasses), or all the classes of an instance, or all the instances of a class.

((:SUBCLASS Layout_info ?a))
((:SUBCLASS :THING ?a))
((:SUPERCLASS Rectangle ?a))
((:INSTANCE Employee ?a))

:DIRECT-CLASS and :DIRECT-INSTANCE

Returns direct classes of an instance, or direct instances of a class.

((:direct-class instance_00067 ?x))
((:direct-instance Editor ?x))

:DIRECT-SUBCLASS and :DIRECT-SUPERCLASS

Returns direct subclasses or superclasses of a class.

((:direct-superclass Author ?x))
((:direct-subclass Author ?x))

:ROOT-CLASS

Returns the root of the ontology tree above any frame.

((:root-class Author ?x))
((:root-class instance_00067 ?x))

:LEAST-COMMON-SUPERCLASS

Returns a class in the KB that is a superclass of both classes and that has no subclass that is also a superclass of both classes. Input can be classes or instances.

((:least-common-superclass Author Section ?lcs))

Algernon Tutorial 2.d Macros involving classes and instances