Nothing is the list - Re: PROPOSAL: Repurpose one key and reserve it for third-party packages

[Jean Louis]

* Emanuel Berg via Users list for the GNU Emacs text editor 
<help-gnu-emacs@gnu.org> [2021-02-13 18:31]:
> Jean Louis wrote:
> 
> > Emacs functions are defined within parenthesis like
> > ( and ). The items withn parenthesis are a list. [...]
> 
> Well, in some sense I suppose, but technically, actually not
> so:
> 
> (listp (defun dummy-function ()
>          (message "darn good software") )) ; nil

That is tricky question.

Anything or nothing between parenthesis is a list.

That it is TRUE that nothing between parenthesis is something, in this
case a list is proven by your similar example of yours:

(listp ()) => t

That sometimes something which is not nothing between the list cannot
be list is proven by your own example:

(listp (defun dummy-function ()
          (message "darn good software"))) => nil

So nothing is a list but something in that list becomes sometimes not a list.