On Monday, February 27, 2017 at 9:50:45 PM UTC+1, parisse wrote: > > I have myself implemented symbolic integration in Giac/Xcas in a spirit > similar to Maxima or Axiom that is a few dozens *algorithms* for some > classes of integrands, then the Risch algorithm in the rational case, like > Maxima while it seems that Axiom implements the more general algebraic > Risch algorithm. It is completely different from these thousands *rules* > (if chapter 1.2.1 is representative of all the rules) : I mean that in an > algorithm you compute, and that reduces the number of cases drastically. > I'm really not convinced that it is worth adding these kind of rules to > Giac/Xcas, but of course I don't speak for other CAS authors. >
The question is if the known algorithms can catch all the cases, and it seems they cannot. While the 1.2.1 example is solved by Wolfram Alpha the Rubi page claims they catch only 60 per cent of all Rubi cases. And I presuppose that if there is an algorithm at all then it is implemented in Alpha. Back to the original proposal. Certainly rules can't catch all cases either. Doesn't this call for a combined approach? As soon as we have rules in Sage they should be called before the best algorithm we have. The default then IMO should be "special rules + Maxima" instead of Maxima alone. Regards, -- 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 https://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
