Explanation of list reference

[Ian Kelly]

On Sat, Feb 15, 2014 at 11:37 AM, Ian Kelly <ian.g.kelly at gmail.com> wrote:
> But what is a set?  Cantor offers this definition:
>
> """
> A set is a gathering together into a whole of definite, distinct
> objects of our perception [Anschauung] or of our thought - which are
> called elements of the set.
> """
>
> But what precisely are "objects" and how are we to determine their
> distinctness?  Cantor above relates them to perception or thought, but
> surely my own perception and thought differ from Cantor's.  If
> mathematics or philosophy offer us any absolute answer to this
> question, I'm unable to find it.

I sent the last message a little too early.  To continue: the above
definition of set is an informal one.  In axiomatic set theory, it
turns out that "set" is simply taken as an undefined primitive.  In
other words: "Set?! We all know what's a set!
Everyone knows what's a set!!"

At some level we have to have primitives, and while we can at some
level delve into the machine in order to define an object in terms of
memory location and layout and lifetime and even physical
considerations such as "which memory?"; at the level of the Python
abstraction I suggest that an object is simply an undefined primitive.