; &gt;
&gt; &gt; I believe that this example is a good answer to the claim
&gt; &gt; that triadic relations can be reduced to dyadic relations
&gt; &gt; by postulating the existence of some new entity ?e.  Although
&gt; &gt; that point may be formally true, Jon's example shows that there
&gt; &gt; is no way of knowing whether that entity is something abstract,
&gt; &gt; such as a set or some hypothetical TitanicTrio, or something
&gt; &gt; concrete such as a Duck.
&gt; 
&gt; I had not seen this before (all 