define-relation [Function]

Purpose

The define-relation function allows the user to procedurally define or redefine a Loom relation.

Syntax

define-relation &key name is is-primitive implies domain domains range arity
predicate function inheritance-link inheritance-method annotations identifier
kb characteristics

Arguments

The name argument is a symbol or string. If name is null, the relation is given a system-generated name.

All of the remaining define-relation arguments are Lisp expressions which evaluate to atoms or lists that are legal arguments to defrelation. Variables appearing in these expressions may evaluate to Loom objects or to the names of such objects.

Value

These functions return the newly-defined (or redefined) relation.

Examples 

(define-relation) ==> |R|BINARY-TUPLE_2 
(define-relation :name "son" :is '(:and child (:range Male))) ==> |R|SON 
(let ((arity 3)) 
  (define-relation :name 'distance :arity arity)) ==> |R|DISTANCE

See Also

Last modified: Dec 28 1995