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A theory in Algernon has a conventional format, which is not strictly
required, but greatly simplifies creation and understanding of the program.
It normally consists of the following five sections.
- Taxonomy: define a containment hierarchy of sets of
objects that appear in the theory and certain individual elements of
- Slots: define the relations that may hold among those objects.
- Rules: define the forward- and backward-chaining inferences that
can take place using those relations.
- Facts: assert the specific facts of the situation to be
reasoned about. Forward-chaining rules invoked by the assertion of these
facts, and backward-chaining rules invoked by the antecedents of those rules,
may cause a significant amount of inference to take place.
- Queries: query the knowledge base for desired information.
Backward-chaining rules invoked by the query, and forward-chaining rules
invoked by assertion of deduced information, may also add additional facts
to the knowledge-base.
The taxonomy and slots together constitute the ontology of the
theory: what objects and relationships are describable within it.
Micheal S. Hewett
Tue Oct 29 10:54:13 CST 1996