2014-06-12 19:10 UTC+02:00, Robert Bradshaw <rober...@math.washington.edu>: > On Thu, Jun 12, 2014 at 8:41 AM, Nils Bruin <nbr...@sfu.ca> wrote: >> On Thursday, June 12, 2014 12:48:37 AM UTC-7, Marc Mezzarobba wrote: >>> >>> Sure. But why not have >>> >>> sage: bool(sin(x)^2+cos(x)^2==1) >>> True >>> >>> return False as well, and let the user test that >>> >>> (rhs-lhs).simplify_full() == 0 >> >> That would probably be even desirable if you want to make SR more >> generally >> usable in sage (imagine, say a cached function with SR elements as >> arguments. You would probably end up with a routine that gets *slower* as >> its cache fills) > > Also, I think we're at least consistent here. Do you have any examples > where > > sage: bool((lhs - rhs).simplify_full() == 0) != bool(lhs == rhs) > > The fact that equality of symbolic expressions is undecidable in > general, and even more limited in implementation, is something that we > just have to live with.
We have to live with them but not to let Sage answers False when it actually does not know the answer... -- 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.
