Undefine functions from parent major-mode

[Thorsten Jolitz <tjolitz@gmail.com>]

Hi List, 

assume there is a major-mode that would serve nicely as a parent-mode
for a new major-mode I want to write, but this parent-mode has lots of
functions/commands, and I would need only a few of them - and must
deactivate the others in the derived mode, because they won't work.

I don't talk about just undefining the keybindings for parent-mode
commands, the redundant functions/commands should simply not be
available anymore in the derived mode, not via 'M-x' and not via 'M-:'.

What is the righ/canonical way to do that?

-- 
cheers,
Thorsten