On Mon, 30 Dec 2019 10:04:53 -0800 (PST), savask <
sav...@yandex.ru> wrote:
> I fully agree that mathboxes material is not that often looked at, but it's
> not hidden in any way either. If someone is eager to contribute to
set.mm,
> they will surely find about mathboxes and material in there. As for tools
> ignoring mathbox theorems, it's a problem of our proof assistants not of
>
set.mm organization, in my opinion.
It's not a *problem*, it's an intentional choice and IIRC it represents an
intentional *change* from how some tools used to work. Because tools can't figure out
how "baked" stuff in the mathboxes is, some tools avoid mathbox material entirely
unless it's specifically requested.
But a lot of the mathbox material *is* ready to be moved into the main body.
It's really a *social* problem that some isn't being moved in, and I hope to
speed things along for the relatively small set of theorems related to these 100 theorems.
> My point is, if the material is not going to be used by anyone but the
> author, is it worth moving it into the main part?
I think that confuses cause & effect. A lot of material in mathboxes won't
be used by other authors because the tools don't point to the material in mathboxes.
Thus, the material that *should* trigger the rule never trigger the "used by two people" rule.
> If someone were, for
> instance, to formalize the four color problem in metamath, would it be
> worth putting such a piece of highly specialized mathematics into the main
> body of
set.mm?
I would say, "of course it should be in the body".
Almost all mathematics is "highly specialized" by some definition
once you move beyond 2+2=4. I believe that most working mathematicians
are also highly specialized by almost any definition.
Also, even if a particular Metamath 100 theorem is unlikely to be reused directly,
I think a vast majority of the materials that the proofs are *based* on are
likely to be reused, so let's get them in the body.
Personally, I don't expect that particular question to show up for a while anyway.
I hear the four-color proof is on the large side :-).
That said, there *is* a proof using Coq
("Formal Proof—The Four-Color Theorem" by Georges Gonthier,
https://www.ams.org/notices/200811/tx081101382p.pdf ).
I don't know if that Coq proof would work in the current version of Coq
(I would love to know either way!). The proof is public, but the
last changes to make it work with an updated Coq date back to 2011. See:
https://github.com/kik/Four-Color-Theorem-Maintenance
And yes, I'd love to see a Metamath proof.
To be fair, at the most there are 100 proofs in "Metamath 100".
So this is really only about a very small set of theorems, compared to all
theorems people may consider. No matter what,
we need to continuously move fully-baked material from mathboxes
to the main body over time as those materials are ready.
I just think that encouraging this to happen with the Metamath 100 theorems
will have the happy result of encouraging some important areas
to be filled into the main body more quickly than they would otherwise.
--- David A. Wheeler