Re: [External] : Re: How to make M-x TAB not work on (interactive) declaration?

[Nick Dokos]

Nick Dokos <ndokos@gmail.com> writes:

> <tomas@tuxteam.de> writes:
>
>> On Mon, Jan 16, 2023 at 12:08:33AM +0300, Jean Louis wrote:
>>> * Rudolf Adamkovič <salutis@me.com> [2023-01-15 23:27]:
>>> > Jean Louis <bugs@gnu.support> writes:
>>> > 
>>> > >> (+) ➜ 0
>>> > >
>>> > > Why? It is wrong.
>>> > 
>>> > In Lisp, the `+' operator returns the sum of the additive identity with 
>>> > all of
>>> > its arguments.  The additive identity equals zero and you provided zero
>>> > arguments.  Hence, you get the additive identity.
>>> 
>>> Send me references on what is additive identity.
>>
>> Identity element [0] as defined in group theory [1].
>>
>> The association of 0 with + and 1 with * runs deeper in maths
>> than you think.
>>
>>> Though that it is so, it does not answer why is it so.
>>
>> Those are, of course, conventions. As whether the natural
>> numbers begin with 0 or 1. But the above is, AFAIK, most
>> widespread among mathematicians, wheter the latter is not.
>>
>> Cheers
>>
>> [0] https://en.wikipedia.org/wiki/Identity_element
>> [1] https://en.wikipedia.org/wiki/Group_theory
>
> The "empty sum" and "empty product" conventions are described in the
> corresponding articles in Wikipedia too - they might help:
>
>    https://en.wikipedia.org/wiki/Empty_sum
>    https://en.wikipedia.org/wiki/Empty_product

Ugh - misposted to the wrong thread. Sorry about that. No idea how I managed 
that.

-- 
Nick