any() and all() on empty list?

[Marcin Ciura]

Georg Brandl wrote:
> Steven D'Aprano wrote:
>>all(flying elephants which are pink) => true
>>all(flying elephants which are not pink) => true
>>
>>So, these flying elephants -- are they pink or not?
> 
> No, you ask two different sets whether they are true.

No, there is only one empty set.
Relevant to this discussion is stuff
about syllogisms concerning non-existent objects
and what C.S. Peirce did to them in the 19th century.
See e.g. http://www.math.fau.edu/schonbek/mfla/mfla1f01syl.html#tth_sEc5
   Marcin