Authors and contributors:

• Chris Mungall (author)

Date: 2012

Document Type: ontology_design_pattern

...

Level of difficulty: advanced

Given

• metaphysis of femur EquivalentTo metaphysis and part_of some femur
• diaphysis of femur EquivalentTo diaphysis and part_of some femur
• metaphysis SubClassOf part_of some diaphysis

It might seem that we should be able to infer:

• metaphysis of femur SubClassOf part_of some diaphysis of femur

But this is not the case, for good reason. The reasoner will infer that a femur metaphysis is both part of a diaphysis and part of a femur, but it cannot rule out that this diaphysis and this femur are only partially overlapping.

We can get the axioms we want by adding additional general axioms:

• (part_of some diaphysis and part_of some femur) SubClassOf part_of some diaphysis of femur

This is not highly intuitive for ontology developers

We instead opt for a heuristic solution. We have a rule that has the antecedents:

• X EquivalentTo PX and part_of some W
• Y EquivalentTo PY and part_of some W
• PX SubClassOf part_of some PY

And consequents:

• X SubClassOf part_of some Y

Note that this rule is not safe. However, they can form the basis of suggestions which can be implemented by the ontology editor.

We might want to automatically generate axioms of this form:

• (part_of some diaphysis and part_of some femur) SubClassOf part_of some diaphysis of femur

Using rules; for example:

IF

• P SubClassOf zone of long bone
• W SubClassOf long bone

THEN generate:

• (part_of some P and part_of some W) SubClassOf part_of some (P and part_of some W)