What Is the Notation for the Incidence Function in Graph Theory?

[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 , 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)

 

[wisvuze]

that is psi, a greek letter

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

 

[woundedtiger4]

that is psi, a greek letter

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

no, this is not

 

[micromass]

no, this is not

Yes, it is.

 

[Jimmy Snyder]

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

 

[WannabeNewton]

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

What is this Sorcery?!

 

[micromass]

What is this Sorcery?!

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

 

[woundedtiger4]

Yes, it is.

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