On Sep 23, 5:36 am, Burcin Erocal <bur...@erocal.org> wrote:
> I think it would be a huge overstatement to say that the symbolics > subsystem in Sage was "designed" in any way. IMHO, it was mostly > patched together to support educational use, then acquired more cruft > through several rewrite attempts and cramped schedules. I think that is true of ALL the subsystems in Sage. In terms of my own interests, that is why the idea of rewriting Maxima in Python is pointless. Wouldn't you prefer to write a system that addressed the shortcomings of Macsyma (etc.) And by shortcomings I don't mean "written in Lisp instead of Python". There are perhaps papers hinting at the Macsyma "assume" system capabilities by Michael Genesereth, but a quick search did not reveal them. The Maple system has a more ambitious capability, but it is still patched on. I do not know where the Mathematica version contains, at the moment. It seems to grow, every so often. But it is still patched on. The note from Tim suggests that (I think) linear inequalities and rectangular regions can encode most conditions of interest. Or maybe polynomial conditions? Certainly not all. And cylindrical algebraic decomposition may be useful, though potentially quite expensive, there is all that other stuff that is not algebraic. Like log, exp, cos, ... > > I am definitely not an expert in this field and have no idea how the > assumptions should work. If you can provide some references, perhaps > these could be used as starting points when/if somebody decides to > work on this. Well, you can probably start with that Maple reference, the next time you design a system. Unfortunately, Sage is already built, and it is probably too late. But Stein is doing something else, so you don't have to worry about him getting in the way. Maybe UberSage; you can call Sage if you need to. > > Here is the only reference I found on this topic: > > http://portal.acm.org/citation.cfm?id=680466 > > The article is available for download here (for those with access): > > http://www.springerlink.com/content/p77364025wh6j7h5/ > > Burcin -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
