Re: Function for deleting a key binding in a sparse keymap

[Richard M. Stallman]

    When starting a minor mode I read some key definitions outside that 
    mode. If they have a certain value I define new values for those keys in 
    that minor mode.

Do you mean that you set them in the minor mode keymap?

    The next time I enter that minor mode the key definitions outside may 
    however be different so I want to remove the key bindings I added when 
    exiting the minor mode.

Why not just construct a new minor mode keymap each time?
You could have a base keymap for the minor mode, which does not change,
and each time you enter the mode you could construct a new keymap
which has that base as its parent.