Math describes (say) a cubic equation.

An algorithm describes how to solve that cubic equation.

Constructing that (or any) algorithm in a way that can be executed by a machine is programming.

Computer science is the analysis of the algorithm - its theoretical time/space efficiency, error bounds, etc.  This much could be considered a branch of mathematics.  Note however that computer science and programming are not actually the same thing.  It is important to have a foundation in computer science if you want to be a good programmer, because it helps you to better design and reason about the algorithms you develop.  But it is not a requirement.

A good programmer may not be (in fact, often is not) a good mathematician, and vice versa.  They are separate identifiable skills.

What does mathematics have to do with programming?
I'm working on an extension that indexes the content of the entry when publish form is submitted, but I need to know if the entry is a new one or an updated one, and in both case, I need the entry_id (the new one juste created or the old one).

Do you know a way to do that? Should I use an other hook?

--Solution--

In fact, entry_submission_end come with 3 parameters: entry_id, meta and data. If the entry is a new one, entry_id contains the new entry_id but $data['entry_id'] is 0, so you can have a condition on that to check if you are editing or creating an entry.
