# Graph theory - notation problem

1. Jun 9, 2012

### woundedtiger4

Hi all,
I don't know if analysis is the right place for me to post this thread therefore please accept my apologies in advance if I am mistaken.
In graph theory the incidence function that associates vertices & edges http://img41.imageshack.us/img41/8171/32004284.jpg [Broken], in the text it has following notation http://books.google.co.uk/books?id=...ce=gbs_ge_summary_r&cad=0#v=onepage&q&f=false at page 2, what do we call to this notation? (it's a v divided by a straight vertical line in the middle)

Last edited by a moderator: May 6, 2017
2. Jun 9, 2012

### wisvuze

that is psi, a greek letter

http://en.wikipedia.org/wiki/Psi_(letter [Broken])

Last edited by a moderator: May 6, 2017
3. Jun 9, 2012

### woundedtiger4

no, this is not

Last edited by a moderator: May 6, 2017
4. Jun 9, 2012

Yes, it is.

5. Jun 9, 2012

### Jimmy Snyder

$$\psi$$
Click the quote button and read what I have posted.

6. Jun 9, 2012

### WannabeNewton

What is this Sorcery?!

7. Jun 9, 2012

### micromass

It is the ancient art of LaTeX. Merely a few know its forms and shapes.

8. Jun 10, 2012

### woundedtiger4

[STRIKE]from what angle it looks psi?[/STRIKE]
ok from now on I will read it as psi