Hi Volker,
On 2014-03-09, Volker Braun <vbraun.n...@gmail.com> wrote:
> "Explicit from the context" is an oxymoron. If you can only be figure it=20
> out from the context, then it is by definition implicit. Only something=20
> that is written down in Python code is explicit in Python.
But what other syntax do you suggest?
Doing
class Cs(Category):
def super_categories(self):
return [Sets()]
*explicitly* states that Cs is a sub-category of the category of sets.
Additionally doing
class Cs(Category):
class Finite(CategoryWithAxiom):
class ParentClass:
def some_method(self):
return "I am a finite c"
is also (I think) *sufficiently* explicit about Cs.Finite() being a
sub-category of Cs(), defined by the axiom Finite.
So, Cs.Finite() is a sub-category of Sets(). Do you think that an
additional explicit statement is needed to tell that Cs.Finite()
additionally is a sub-category of Sets.Finite()?
I believe that the rule implemented in #10963
"Cs().SomeAxiom() is a sub-category of SCs().SomeAxiom() for all
super-categories SCs() of Cs() to which SomeAxiom can be applied"
is clear enough.
What I am really not happy about is that in some cases (or in all? If
not in all, then in what cases?) Cs.Finite is overridden in Cs() by a
cached method.
Nicolas hasn't answered yet if documentation respectively semantic
specification of the "Finite" axiom is the only reason for this highly
intransparent trick. If it is, then I think it would be better to turn
axioms into objects (currently they are just names) carrying their own
documentation and specification.
Best regards,
Simon
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