<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0//EN" "http://www.w3.org/TR/REC-html40/strict.dtd"><html><head><meta name="qrichtext" content="1" /><style type="text/css">p, li { white-space: pre-wrap; }</style></head><body style=" font-family:'DejaVu Sans'; font-size:9pt; font-weight:400; font-style:normal;">On Sat, 13 Jun 2009, John Yeung wrote:<br>
> On Jun 13, 5:22 pm, "Rhodri James" <rho...@wildebst.demon.co.uk><br>
><br>
> wrote:<br>
> > Such an understanding would be clearly wrong in the context<br>
> > in which we were talking (and denotational semantics is a<br>
> > branch of category theory, which is not specific to computer<br>
> > science if you don't mind). If None is nothing, then it can't<br>
> > be a string, int, float or anything else, because they're all<br>
> > something.<br>
><br>
> I appreciate your explanation, and your politeness.<br>
><br>
> And I accept your answer, as well as Steven's and Paul's for that<br>
> matter. I still think it is understandable (and people may choose to<br>
> understand in a condescending way, if they wish) that someone might<br>
> not get the difference between what you are saying and the statement<br>
> that all elements of the empty set are floats. I mean, what's in the<br>
> empty set? Nothing. But you've said that floats are something. How<br>
> is it that nothing is something?<br>
[...]<br>
<p style="-qt-paragraph-type:empty; margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;"><br></p>Also accepting that Python's implementation of None and all() are well-defined and practical, I would add that philosophically these matters of emptiness and nothingness are far from concluded. Bertrand Russell, for one, would have disputed the behaviour of all([]), although he may have appreciated its usefulness.<br>
<p style="-qt-paragraph-type:empty; margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;"><br></p>Regards,<br>
<p style="-qt-paragraph-type:empty; margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;"><br></p>John<br>
<p style="-qt-paragraph-type:empty; margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;"><br></p><p style="-qt-paragraph-type:empty; margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;"><br></p></body></html>