(Q24017414)
English
second-order class
metaclass containing as instances all classes of individuals
- metaclass of the 2nd order
- 2nd-order metaclass
- metaclass (2nd order)
- second-order metaclass
- metaclass (second order)
- metaclass of the second order
- metaclass of the first order
- 1-order metaclass
- 2nd-order class
Statements
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Wikidata:WikiProject Ontology/Modelling (multiple languages)
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A second-order class in Wikidata, e.g., watercraft type (Q16335899), bridge by structural type (Q17644823), or first-order class (Q104086571), is a class all of whose instances are implicitly or explicitly an instance of (P31) first-order class (Q104086571). A class is implicitly a second-order classes if it is a subclass of (P279) another class that is a second-order class, e.g., submarine type (Q121289744) is implicitly a second order class because it is a subclass of (P279) watercraft type (Q16335899). These implicit instance of instance of (P31) statements are not all observable in Wikidata. Before stating that a class is an instance of (P31) second-order class (Q24017414) check that it is actually a second-order class, i.e., that all its instances are classes of individuals. (English)
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Identifiers
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Wikipedia(1 entry)
- enwiki Second-order class