orbital.logic
Interface Relation

All Superinterfaces:

Callback

public interface Relation
extends Callback

This basic Relation interface tags interfaces and classes that describe relations (or predicates) between objects. A general relation over a set M is of the form:

~ ⊆ M×M
relation: for a,b being objects, a ~ b is consistently either true or false.

A Relation is any relation-like method contained in an Object with an invocation-signature like

   public boolean related(arg-type,arg-type)
 

Of course, relations could also be defined for more than two objects. They might as well be implemented as Predicate-Functors P where P(a,b) is true if a ~ b and false otherwise. A pseudo-Prolog definition for this would be P(a,b) :- a~b.

Refer to BinaryPredicate for properties of relations.

Evolves: This interface might be unified with Predicates, most likely BinaryPredicates.

Author:

André Platzer

See Also:

BinaryPredicate, Functor, Callback