Jonathan de Boyne Pollard wrote:
>>> That might explain it, I guess. So if I see something before me that I
>>> am inclined to refer to as a "coffee cup", how am I to tell whether or
>>> not it actually _is_ a coffee cup in some essential way?
>>
>> In fact, it could be your doughnut.
>>
>> (Old topology joke.)
>
> My doughnuts are generally not continuously deformable to coffee cups.
> I'd have to poke them with a stick to make that true, and that would
> squirt jam everywhere.

Would topology have still been the field it is today if doughnuts had
not existed?

--
Peter Moylan, Newcastle, NSW, Australia. http://www.pmoylan.org
For an e-mail address, see my web page.