ve a
&gt;temporal parameter. Good luck with adapting ZF (or any other known
&gt;set theory) to include temporal reasoning. (And what else is down
&gt;that road? Situations? points of view?)
&gt;CP: Pat, does this mean you take option 3 above?
&gt;
&gt;Ordinary language is a lousy guide to ontological coherence, as I've
&gt;said before. If the idea of 'set' were clear in NL, then people like
&gt;Russell and Whitehead would have had a much easier time.
&gt;
&gt;CP: I agree about ordinary language. But I think