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The transformation from the OWL refset to OWL ontology document should process description file and language refset when descriptions are included. They should be represented by the following annotation properties for a given language refset.

• • rdfs:label - if present, it is RF2 fully specified name
  • skos:prefLabel - if present, it is RF2 preferred term
  • skos:altLabel - if present, it is RF2 acceptable synonym
  • skos:definition - if present, it is RF2 definition
• Declaration

Declarations Most declarations are excluded from the OWL refset to avoid duplication to the content that are represented by the RF 2 concept file.

• • Declarations for the built in entities, e.g. owl:Thing, owl:Nothing, are excluded from the OWL Refset because they are implicitly presented in every OWL 2 ontology.
  • Class declarations are excluded from the OWL Refset because the Concept file represents the same information. 138875005 |SNOMED CT Concept (SNOMED RT+CTV3)| is the only concept needs to be declared in the OWL axiom refset.
  • Property declarations should be included in the OWL axiom Refset to reduce the implementation burden for deriving such information at runtime.

Concept Defined by Axiom

The OWL Axiom Reference Set is designed to cover all logic definitions of SNOMED CT. A concept can be defined by one or more axioms in the same module or different modules. OWL Axioms are statements that indicate what is true in the domain. 

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