an be expressed by a predicate.
But in any case, I'm not sure what it means to "use" anything "as a
property."

&gt; where this can be true at one time, and not at another. I do not need
&gt; this, since 4D takes time into account already.

&gt; &gt; &gt;  - how one individual stands to another is modelled by relation
&gt; &gt; &gt;  instances
&gt; &gt;
&gt; &gt; You mean you model one thing x standing in relation R to another
&gt; &gt; thing y by including the pair &lt;x,y&gt; in the set that represents (o