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Sigma KEE - KappaFn
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
to a variable and a formula is the
of things that satisfy the formula. For example, we can denote the
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.
Properties or qualities as distinguished from any particular embodiment of the properties/qualities in a physical medium. Instances of Abstract can be said to exist in the same sense as mathematical objects such as sets and relations, but they cannot exist at a particular place and time without some physical encoding or embodiment.
s that require two arguments.
The universal class of individuals. This is the root node of the ontology.
is a term-forming
that maps from a n-tuple of arguments to a range and that associates this n-tuple with at most one range element. Note that the range is a
, and each element of the range is an instance of the
The class of
s whose properties can be inherited downward in the class hierarchy via the
partial valued relation
just in case it is not a
, i.e. just in case assigning values to every argument position except the last one does not necessarily mean that there is a value assignment for the last argument position. Note that, if a
is both a
, then it is a partial function.
of relations. There are two kinds of
s both denote sets of ordered n-tuples. The difference between these two
es is that
s cover formula-forming operators, while
s cover term-forming operators.
single valued relation
just in case an assignment of values to every argument position except the last one determines at most one assignment for the last argument position. Note that not all
s relate three items. The two
Belongs to Class
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