On Wednesday, January 20, 2016 at 3:22:54 PM UTC-8, Dima Pasechnik wrote: > > > to me, two fields that are specified by the same irreducible polynomial > over the same prime subfield ought to be identical. > it'd be much better design, not wedding them to named generators at all. > > That's not compatible with the coercion model in sage where
Z['x'] coerces into QQ['x'] and QQ['u','x','v'], but not into QQ['y'] Names of generators are part of the identity of a structure in sage. With respect to polynomial rings this allows for various automatic behaviours that are out of reach for other computer algebra systems, so we are getting a benefit from it. It also has unfortunate and/or counterintuitive consequences in other cases; for you this may be one of them. It'll be way too invasive to change sage's concepts at this stage, so I think we'll have to live with it. Currently the generator name is important for finite fields: sage: GF(64,'x').0+GF(64,'y').0 TypeError: unsupported operand parent(s) for '+' -- 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 [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
