nth-domain has 1 Entity 2 Entity)
&gt; &gt;
&gt; &gt; (documentation "AXIOM: Absurdity is a class.")
&gt; &gt;
&gt; &gt; (Class Absurdity)
&gt; &gt;
&gt; &gt; (documentation "AXIOM: Absurdity has no instances.")
&gt; &gt;
&gt; &gt; (not (exists (?x) (instance-of ?x Absurdity)))
&gt; &gt;
&gt; &gt; (documentation "AXIOM: Absurdity is a subclass of every class.")
&gt; &gt;
&gt; &gt; (forall (?c)
&gt; &gt;         (=&gt; (Class ?c)
&gt; &gt;             (subclass-of Absurdity ?c)))
&gt; &gt;
&gt; &gt; (documen