ubt.  Yes, of course, people are able to recite
&gt; &gt; the phrase that "a relation is a set of tuples", but whether they
&gt; &gt; can follow up any significant number of the consequences of that
&gt; &gt; token tenet, and whether they can recognize a tuple in many of
&gt; &gt; its sundry disguises, those are different questions altogether.
&gt; &gt;
&gt; &gt; Anyway, while I was pondering, weak and weary, this whole problematic
&gt; &gt; scene, I happened to recall a sort of a pedagogical moment from my