On Thu, Oct 1, 2015 at 9:38 AM, Bill Page <bill.p...@newsynthesis.org> 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
Just curious -- Bill Page, did you ever take a graduate mathematics course in "category theory", or at least a course that had a significant portion devoted to it, or at least carefully read (and did exercises!) from a textbook on category theory? Because despite being called "abstract nonsense" by some, category is a serious, highly technical, and nontrivial area of mathematics, with interesting theorems, a long development, etc., just like other areas of math. I would expect that somebody who doesn't know category theory (the mathematical area) would find the category framework in Sage very confusing, just like somebody who doesn't know calculus might find the symbolic functionality confusing. -- William > 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 <goodwillh...@googlemail.com> 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. -- William (http://wstein.org) -- 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.