*CardinalityFn* | *documentation* (*CardinalityFn* ?CLASS) returns the number of instances in the Class or Collection ?CLASS | |

**has axiom** (=> (*and* (*instance* ?COUNT Counting) (agent ?COUNT ?AGENT) (*patient* ?COUNT ?ENTITY)) (exists (?NUMBER) (*knows* ?AGENT (*equal* (*CardinalityFn* ?ENTITY)))))
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**has axiom** (=> (*instance* ?SET FiniteSet) (exists (?NUMBER) (*and* (*instance* ?NUMBER NonnegativeInteger) (*equal* ?NUMBER (*CardinalityFn* ?SET)))))
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**has domain1** (*UnionFn* Class Collection) | |

**has domain2** NonnegativeInteger | |

**is an ***instance* of AsymmetricRelation | |

**is an ***instance* of UnaryFunction | |

BinaryRelation | **is first ***domain* of *DomainFn* | |

**is first ***domain* of *equivalenceRelationOn* | |

**is first ***domain* of *inverse* | |

**is first ***domain* of *irreflexiveOn* | |

**is first ***domain* of *partialOrderingOn* | |

**is first ***domain* of *RangeFn* | |

**is first ***domain* of *reflexiveOn* | |

**is first ***domain* of *totalOrderingOn* | |

**is first ***domain* of *trichotomizingOn* | |

**is second ***domain* of *inverse* | |

Function | **is first ***domain* of *AssignmentFn* | |

**is first ***domain* of *closedOn* | |

**is first ***domain* of *range* | |

**is first ***domain* of *rangeSubclass* | |

Class | **is third ***domain* of *domain* | |

**is third ***domain* of *domainSubclass* | |

Abstract | **is ***disjoint* from Physical | |