 can hardly be
&gt; claimed by Jon (or anyone else) to be any kind of *demonstration*
&gt; of some kind of irreducibility.  At most, it could show that some
&gt; distinction that Jon (or someone) has in mind, cannot be represented
&gt; in the formal notation.  To get from that to an irreducibility result
&gt; requires showing that the distinction *can* be represented in some
&gt; other formalism.  Good luck with the mathematical theory of ducks,
&gt; whoever sets out to show this.

These examples, which wer