Strange behavior of atom(), cont'd



Thanks to Richard and Michel for clarifying.

What gave rise to my question was that I was trying to find a way, from within 
a Maxima file that I load, to tell if a needed package had already been loaded, 
or if I needed to load it.

I was trying to use atom() to see if a function in the package was defined,
and if not, to load the package.  Specifically, I was testing the function
random_continuous_uniform(0,1,1) in "distrib".

Is there a better way to detect if a package/file has already been loaded into 
Maxima?

Kostas