On Thursday, 1 October 2015 10:32:43 UTC-7, Bill Hart wrote: > > Thanks for the quick reply Bill. > > Your comments make more sense (to me) now, since I see that your concerns > are more about the way categories are handled in Sage, or at least how it > interacts with the parent/element system. > > At this stage there is no category theory in Nemo (it wouldn't be > appropriate in Julia itself, since that is a general purpose language, not > really a CAS). > > There is a Nemo development list by the way. It's nemo-devel on Google > Groups. It's public, so anyone can request to join. > > If you prefer to discuss it further there, you are most welcome. Though I > must warn that Nemo is a very new system and there are no efforts started > or planned for category theory. > > Nemo isn't trying to be the next Sage, so it's not even clear that > thinking about categories in Nemo is even meaningful. Nemo exists primarily > to do something innovative for that part of computer algebra/number theory > that requires very fast generics. That doesn't really cover category theory > I don't think. > > However, our group in Kaiserslautern is good friends with the group in > Achen doing HomAlg and Cap, which are category theory projects making use > of Gap 4. There may be some interaction between us and them in the future, > since at the very least we plan to interface with Gap. >
One probably can do a Julia interface to libGAP relatively easily. Did you look into this? Dima > > Bill. > > On 1 October 2015 at 18:38, Bill Page <bill...@newsynthesis.org > <javascript:>> wrote: > >> [Changed thread subject from: Sources of funding - perhaps computer >> manufacturers? ] >> >> What I find hard to swallow is the peculiar mix of "parent", >> "category", and Python data types (class system and inheritance). In >> spite of the available documentation in the category system in Sage, I >> really don't know what to use when and how to map it properly to >> abstract mathematics in such a way as to gain as much as possible from >> the existing Sage libraries. The situation is very different in >> Axiom/Aldor. >> >> It is good that you mention Aldor because it was designed specifically >> as the "next generation" of Axiom library compiler but for entirely >> non-technical reasons never achieved this status. On the other hand >> the Aldor documentation is still the best available documentation of >> the Axiom type system. >> >> http://www.aldor.org/docs/aldorug.pdf >> >> Aldor is currently supported only by the FriCAS fork of Axiom. Aldor >> development itself is not dead, merely sleeping, and apparently a low >> priority for the several people involved. >> >> https://github.com/pippijn/aldor >> >> To the best of my knowledge the Sage-combinat development of the >> category system in Sage was motivated largely by the experience of >> some of the developers with the Axiom-like category system that was >> implemented in MuPad. MuPad was originally modeled after an early >> version of Maple and so far as I know has a syntactic/symbolic >> orientation at it's core (like Maple, Mathematica and Maxima) rather >> than a more "algebraic" one. The MuPad developers borrowed from Axiom >> in developing a more static type-oriented architecture for the >> library. Maple itself as you might know has taken a rather different >> approach. But in any case, compared to Axiom, the MuPad category >> systems seems to me to be more or less grafted-on. And the Sage >> category system seems much more so. >> >> The little that I know about the Julia type system, mostly from >> discussions about Axiom and Aldor on that mailing list about a year >> ago, is that it has a more malleable design that one might expect to >> enable a more integrated implementation of the central ideas of the >> Axiom category system. So far as I know however no one is working on >> this specifically. >> >> --- >> >> I am happy to continue the discussion of Axiom, Aldor and FriCAS but I >> am not sure if this discussion is entirely appropriate the the >> sage-devel list. Is there a Julia/Nemo list where this should be >> continued? >> >> Regards, >> Bill Page. >> >> >> On 1 October 2015 at 10:56, Bill Hart <goodwi...@googlemail.com >> <javascript:>> wrote: >> > >> > On Thursday, 1 October 2015 16:35:20 UTC+2, Bill Page wrote: >> > <SNIP> >> >> >> >> Unfortunately while I am very much in favor of the category/domain >> >> approach of Axiom and related systems, I find the Sage implementation >> >> of this idea almost entirely indigestible. Perhaps this is not the >> >> case for a sufficiently large number of potential Sage developers. >> > >> > Bill, I would be very interested if you could elaborate on this point >> in >> > more detail (assume I don't know anything about Aldor/Spad because it >> is so >> > long ago that I read the manual for Aldor that I really have forgotten >> how >> > this works over there). >> > >> > I'm currently implementing a system in Julia which really follows the >> design >> > of Sage's parent/element setup quite closely (we tried another >> approach, but >> > it failed). Since the project I'm working on is yet very young, I'd >> like to >> > understand what is unpalatable about the Sage approach, since I'm >> > essentially using it. >> > >> > > -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-devel@googlegroups.com. Visit this group at http://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
