[Python-Dev] (Don't Read If You're Busy With 2.1b2) "Rich" Comparisons?

Martin v. Loewis martin@loewis.home.cs.tu-berlin.de
Sat, 24 Mar 2001 09:19:44 +0100


>> The mathematical definition for max() I learned in Calculus 101 was
>> "the smallest element which is > then all arguments"
>
>Then I guess American and Dutch calculus are different.
[from Israeli calculus]

The missing bit linking the two (sup and max) is

"The supremum of S is equal to its maximum if S possesses a greatest
member."
[http://www.cenius.fsnet.co.uk/refer/maths/articles/s/supremum.html]

So given a subset of a lattice, it may not have a maximum, but it will
always have a supremum. It appears that the Python max function
differs from the mathematical maximum in that respect: max will return
a value, even if that is not the "largest value"; the mathematical
maximum might give no value.

Regards,
Martin