Transformation patterns are serialized according to an XML schema, http://nb.vse.cz/~svabo/patomat/tp/tp-schema.xsd The representation of ontology patterns is based on OWL 2. However, while an OWL ontology refers to particular entities, e.g. to class Person, in the patterns we generally use placeholders. Entities are specified (i.e. placeholders are instantiated) at the time of instantiation of a pattern.
op1/2 element contains entity declarations. In declaration, each entity is identified with a placeholder which is a replaced with name of entity (fragment URI) when ontology pattern is instantiated in the case of source ontology pattern (op1). Regarding target ontology pattern, entity names are deduced from entity names of op1 and specification within pattern alignment. Every placeholder has its type which can be basically any type from OWL 2 specification. Furthermore, there are axioms capturing logical structure of ontology pattern. There can also be annotation axioms. Finally, there can be ndp element, naming detection pattern, which can support ontology pattern detection, see Section 5. Although multiple alternative naming patterns could be employed for detection of ontology pattern occurrence, our current implementation supports at most one naming pattern.
One link corresponds to one element. Currently, there are basically two types of transformation links:
A transformation pattern is E, Ax, NDP, LI,NTP, E, Ax, NDP.