n of: #$Relation-MathematicalObject <br />
	    direct generalization of: #$BinaryFunction #$QuintaryFunction #$UnaryFunction #$QuaternaryFunction #$TernaryFunction #$FixedArityFunction #$OneToOneFunction</p>
<p>#$EvaluatableRelation   evaluatable relations</p>
<p>    A specialization of #$Relation. Each instance of #$EvaluatableRelation is a function or predicate for which there is some piece of system code that can be invoked to evaluate (i.e. to determine the denotation or truth-value of) a clos