Hi Rob, On 25 Jun., 02:44, Rob Beezer <goo...@beezer.cotse.net> wrote: > I'm having trouble with the construction of a list of vector spaces > with the Sequence() command. > > Is this a bug, or misuse/abuse? Failure, followed by a bit of a > workaround.
First, I thought that Sequence is supposed to be used on elements of a common parent, whereas you use it on objects of a common category. But apparently that is fine (i.e., no misuse), because you can do sage: L = [QQ^2, RR^2] sage: Sequence(L) [Vector space of dimension 2 over Rational Field, Vector space of dimension 2 over Real Field with 53 bits of precision] sage: Sequence(L).universe() Category of objects or: sage: L = [QQ^2, ZZ^2, QQ^2] sage: Sequence(L) [Vector space of dimension 2 over Rational Field, Ambient free module of rank 2 over the principal ideal domain Integer Ring, Vector space of dimension 2 over Rational Field] sage: Sequence(L).universe() Category of objects So, I would say that what you did should work, and it is a bug. And I see a second bug: sage: Sequence([ZZ['x'],QQ]).universe() Category of objects That should better be the category of commutative rings, isn't it? Hence, when called on objects of a category, Sequence might think of using the meet of the categories. Would that be doable? Cheers, Simon -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
