On 23 October 2016 at 15:28, vdelecroix <20100.delecr...@gmail.com> wrote: > Le dimanche 23 octobre 2016 16:20:25 UTC+2, John Cremona a écrit : >> >> I see that despite the title of that ticket, this is (at present) >> about r%n when r =p/q is rational. > > > The ticket also cares about the case where n is rational. Moreover my > proposed branch makes % part of the coercion system (when one of the > argument is rational). So standard coercion rules apply.
OK > > However, concerning this thread, my question is about r%n with r=p/q being > rational. > >> Questions: >> >> 1. What is the proposed behaviour when q is not invertible modulo n? >> Or more generally, if q*x=p (mod n) has no solutions, or more than >> one solution (mod n)? > > > The very same behavior as with the two implementation I proposed. In other > words, raise the same errors as inverse_mod does when it complains. OK and this should be documented somehow, though I'm not sure how to document the behaviour of operators. > > Concerning the non-uniqueness, it is just a matter of having an extra > argument to inverse_mod on integers and using it here. Do you think it might > be useful? No, anyone wanting all solutions would be able to get them a different way. > >> >> 2. Is the output going to be an element of Z/nZ, or of Z (as your >> sample code suggests)? > > > I was thinking about Z since for Z/nZ the direct conversion just works > Zmod(n)(r). That's reasonable, and what people would expect with an operator such as %. thanks for the answers. As for you question, do we need a name to shadow the operator %? If we do, then "mod"? > > Vincent > > -- > 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. -- 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.
