Format of Pids

[Vance Shipley]

What can be said about the format of Pids?

Pids (and references and ports) look like: 

	<0.11.0>

These numbers seem to be refered to as num,
serial and creation.  What do these things 
mean?  

I am working with them in erl_interface and
would like to understand them better.  For 
instance if I want to quickly test if a Pid
exists I could do if(pid->serial).  But is
that right or is num the right field to check?
Or do I really have to compare the whole
structure?  

I seem to see that the first field is '0' if
the Pid is local and something else if it's 
remote.  Is that number the same on other 
nodes?  I assume that these Pids are munged
on the way through the distribution.

Just curious ...

	-Vance