*KappaFn* | *documentation* A class-forming operator that takes two arguments: a variable *and* a formula containing at least one unbound occurrence of the variable. The result of applying *KappaFn* to a variable *and* a formula is the Class of things that satisfy the formula. For example, we can denote the Class of prime numbers that are less than 100 with the following expression: (*KappaFn* ?NUMBER (*and* (*instance* ?NUMBER PrimeNumber) (*lessThan* ?NUMBER 100))). Note that the use of this function is discouraged, since there is currently no axiomatic support for it | |

**has domain1** SymbolicString | |

**has domain2** Formula | |

**has ***range* Class | |

**is an ***instance* of BinaryFunction | |

BinaryFunction | **has axiom** (*<=>* (*and* (*holds* ?REL ?INST1 ?INST2 ?INST3) (*instance* ?REL BinaryFunction)) (*equal* (*AssignmentFn* ?REL ?INST1 ?INST2) ?INST3))
| |

**has axiom** (=> (*and* (*closedOn* ?FUNCTION ?CLASS) (*instance* ?FUNCTION BinaryFunction)) (forall (?INST1 ?INST2) (=> (*and* (*instance* ?INST1 ?CLASS) (*instance* ?INST2 ?CLASS)) (*instance* (*AssignmentFn* ?FUNCTION ?INST1 ?INST2) ?CLASS))))
| |

**has axiom** (=> (*and* (*instance* ?FUNCTION BinaryFunction) (*equal* (*AssignmentFn* ?FUNCTION ?ARG1 ?ARG2) ?VALUE1) (*equal* (*AssignmentFn* ?FUNCTION ?ARG1 ?ARG2) ?VALUE2)) (*equal* ?VALUE1 ?VALUE2))
| |

**has axiom** (=> (*and* (*instance* ?FUNCTION RelationExtendedToQuantities) (*instance* ?FUNCTION BinaryFunction) (*instance* ?NUMBER1 RealNumber) (*instance* ?NUMBER2 RealNumber) (*equal* (*AssignmentFn* ?FUNCTION ?NUMBER1 ?NUMBER2) ?VALUE)) (forall (?UNIT) (=> (*instance* ?UNIT UnitOfMeasure) (*equal* (*AssignmentFn* ?FUNCTION (*MeasureFn* ?NUMBER1 ?UNIT) (*MeasureFn* ?NUMBER2 ?UNIT)) (*MeasureFn* ?VALUE ?UNIT)))))
| |

**has axiom** (=> (*instance* ?FUNCTION BinaryFunction) (*valence* ?FUNCTION 2))
| |

**is first ***domain* of *distributes* | |

**is first ***domain* of *identityElement* | |

**is second ***domain* of *distributes* | |

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

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

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