# Tagged Questions

**23**

votes

**9**answers

2k views

### Is the empty graph a tree?

This is a boring, technical question that I stumbled upon while making a contribution to Sage. I would still like to hear a constructive answer so hopefully the question does not get closed.
The ...

**21**

votes

**4**answers

2k views

### When is it appropriate to entitle a paper “A note on…” or “On the …”? [closed]

I rarely find modern research papers (on mathematics) that are less than 5 pages long. However, recently I came across a couple of mathematical research papers from the 1960/1970's that were very ...

**10**

votes

**6**answers

6k views

### A symbol to denote the set of prime numbers ?

It strikes me that there is no widely accepted symbol to denote the set of usual prime numbers in $\mathbb{N}$.
Look:
$$\zeta(s)=\prod_{p\in \mathrm{?}}\frac{1}{(1-p^{-s})}$$
Wouldn't it be nicer ...

**24**

votes

**19**answers

8k views

### Math paper authors' order

It seems in writing math papers collaborators put their names in the alphabetical order of their last name. Is this a universal accepted norm? I could not find a place putting this down formally.