Relationships
Works and themas have a Many-to-many (data model) relationship, meaning that any work can have more than one subject, and any subject can be expressed in one or more works. The same is true for the relationship between thema and nomen. A thema can be expressed in many different ways and a nomen can express many different themas, all depending on the given system. Besides these relationships, the workgroup has so far identified several other thema-thema and nomen-nomen relationships. Two nomens can, for example, be said to have an equivalence relationship, if they both are appellations of the same thema.
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