Hi Nils, On 2014-03-07, Nils Bruin <nbr...@sfu.ca> wrote: > Shouldn't that be "Does Sage know that R is a finite set *by=20 > construction*?" If the "is_finite" result gets cached in the categories=20 > we'd violate immutability of parents, i.e.,
I think that that is not to happen. Instead, if Sage knows by construction that R is finite, then R in FiniteSets() returns True, and moreover R inherits a method is_finite() that immediately returns True (but it does not override a custom is_finite() method that R might have inherited from somewhere else). Fine. But if Sage does not know by construction that R is finite, then R in FiniteSets() currently does return False (and should do so in future), even if R.is_finite() returns True after a lengthy computation (that hopefully is cached). > I know there are some cases where we've swallowed this=20 > badness in favour of some gains in efficiency elsewhere. It seems that was the worst idea I ever had. Sorry. Best regards, Simon -- 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.