Just to tell you what you already know, the symbolic ring is the parent of last resort if there is nothing more specific. So its to be expected that you don't have any canonical maps elsewhere.
Pynac should probably unwind the comparison of two wrapped (non-symbolic) python objects to the comparison of the underlying python objects. Haven't tried that, though. You have to be careful about infinite recursions, the comparison might again coerce into the symbolic ring. On Sunday, February 22, 2015 at 11:02:44 AM UTC+1, Ralf Stephan wrote: > > Hello, > a long standing issue is > > sage: bool(pi<Infinity) > False > sage: bool(SR(3)<Infinity) > False > > http://trac.sagemath.org/ticket/12967 > at which I'm having a naive stab (because it interferes with #14801). > Maybe I can learn something? > > In the ticket the problem has been said having to do with Pynac, > but I don't think so. It would all work nicely if, instead of the > expression > object, its underlying `pyobject` would be compared. But this does not > happen because there is no coerce map from `SR` to `InfinityRing`. > > So, can we somehow have an indirect coercion map that uses not > the parent but the parent of something a member function (like `pyobject`) > returns? The problem of SR having no canonical map to anything > in spite of some expressions being well behaved is the source of > much frustration. > > Regards, > -- 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.
