Relationships




Instances  abstract  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. 
 binary predicate  A Predicate relating two items  its valence is two. 
 binary relation  BinaryRelations are relations that are true only of pairs of things. BinaryRelations are represented as slots in frame systems. 
 entity  The universal class of individuals. This is the root node of the ontology. 
 equivalence relation  A BinaryRelation is an equivalence relation if it is a ReflexiveRelation, a SymmetricRelation, and a TransitiveRelation. 
 inheritable relation  The class of Relations whose properties can be inherited downward in the class hierarchy via the subrelation Predicate. 
 predicate  A Predicate is a sentenceforming Relation. Each tuple in the Relation is a finite, ordered sequence of objects. The fact that a particular tuple is an element of a Predicate is denoted by '(*predicate* arg_1 arg_2 .. arg_n)', where the arg_i are the objects so related. In the case of BinaryPredicates, the fact can be read as `arg_1 is *predicate* arg_2' or `a *predicate* of arg_1 is arg_2'. 
 reflexive relation  Relation ?REL is reflexive iff (?REL ?INST ?INST) for all ?INST. 
 relation  The Class of relations. There are two kinds of Relation: Predicate and Function. Predicates and Functions both denote sets of ordered ntuples. The difference between these two Classes is that Predicates cover formulaforming operators, while Functions cover termforming operators. 
 symmetric relation  A BinaryRelation ?REL is symmetric just iff (?REL ?INST1 ?INST2) imples (?REL ?INST2 ?INST1), for all ?INST1 and ?INST2. 
 transitive relation  A BinaryRelation ?REL is transitive if (?REL ?INST1 ?INST2) and (?REL ?INST2 ?INST3) imply (?REL ?INST1 ?INST3), for all ?INST1, ?INST2, and ?INST3. 
Belongs to Class

entity 
  