It must be possible to say that a connection is of a certain type. He introduces a relation Cx , y to express that individuals x and y are connected. Unfortunately, given this relation, it is only possible to express that there are two connections between two individuals when connections are regarded as a special kind of individuals themselves. We have therefore introduced connections as a relation between individuals and reified the relation into the connection concept to allow for multiple connections that can be typed. This ontology provides the means to express that individuals are connected.
Axioms ensure that only sound connections can be made.
These axioms take into account the possible part-of decomposition an individual can have. The projection performed in this ontology is of the type include and extend . Inclusion is done in line 2 and the extension takes shape by definition of new concepts and relations that use mereology in their axioms. This yields an ontology that has the same level of abstraction as the included mereology. There are three axioms concerning connections.