Just for the record: > On Aug 17, 2020, at 06:40 , Nils Bruin <nbr...@sfu.ca> wrote: > > On Monday, August 17, 2020 at 6:04:41 AM UTC-7, John Cremona wrote: > I'm sure this used to work: > > sage: F = GF(2) > sage: r = 5/3 > sage: F(1)*r > TypeError: unsupported operand parent(s) for *: 'Finite Field of size > 2' and 'Rational Field' > > Of course I know that the could not be a coercion from QQ to GF(2) but > there is a conversion which works fine (when the denominator is odd): > > It would surprise me if this used to work. Perhaps a LONG time ago? It > shouldn't work, because of the reason you mention [conversions aren't used > for figuring out common parents]. What *does* work is
Depends on what LONG means :-}. I tried a couple of different versions back to sage-2.11, and all fail with the same error message. > > F(1)*5/3 > > because it's parsed as (F(1)*5)/3: dividing by integers is something that > GF(2) allows. This did work as well in 2.11 :-} HTH Justin -- Justin C. Walker Director Institute for the Enhancement of the Director's Income -- Fame is fleeting, but obscurity just drags on and on. F&E -- 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 view this discussion on the web visit https://groups.google.com/d/msgid/sage-devel/AAD2BD78-6A9E-456B-8AD2-2EBFD393E664%40mac.com.