On Tuesday, June 19, 2018 at 10:35:46 PM UTC-7, Ralf Stephan wrote: > > On Wednesday, June 20, 2018 at 12:22:07 AM UTC+2, Nils Bruin wrote: >> >> Of course, another solution for your computation to succeed is to not put >> the assumptions in. Inequalities will not affect matrix algebra >> computations. (only decisions are made based on whether something is >> *equal* to zero) >> > > Really? Maxima's proving algorithm might need the assumptions, e.g. > > sage: (sqrt(x^2)-x).simplify() > -x + sqrt(x^2) > sage: assume(x>0) > sage: (sqrt(x^2)-x).simplify() > 0 >
Thanks for the example! Indeed, multi-valued functions might need inequalities to have their branch cuts resolved. However, the entries in the matrix are all rational functions, so branch cuts shouldn't come into play. Since the arithmetic in rational function fields doesn't need topology or an ordering, inequalities shouldn't actually affect the computation of an inverse matrtix. -- 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.
