How to save all global variables using the save command.



There is a save command in maxima.

I normally use "save (filename, all)" to store the current state of Maxima.
This includes all user-defined variables, functions, arrays, etc., as well
as some automatically defined items


Is there a way to save only those global variables. I do not want to save
user defined functions as I will modify them frequently after the saving.


Leo