On Tue, May 27, 2014 at 09:14:03PM +0200, Vincent Delecroix wrote: > A module over ZZ is the same thing as an Abelian group. Why do we have > two distinct categories ?
This issue is mentioned on http://trac.sagemath.org/wiki/CategoriesRoadMap. So far, the two categories have not been merged for a stupid bootstrapping reason: to construct Modules(ZZ), we need to construct ZZ. To construct ZZ, an abelian group, we need to construct the category CommutativeAdditiveGroups(). So if the latter is an alias for Modules(ZZ), we are stuck. This is basically the same reason why QQ is not in Algebras(QQ) [1] It might be possible to break the loop with some lazyness. If someone cares enough to investigate, please! Cheers, Nicolas [1] For that one, thanks to #15801, we could possibly put QQ in Algebras(Fields()) if we believe this is useful. But not yet have Fields() be a subcategory of Algebras(Fields()). -- Nicolas M. Thiéry "Isil" <nthi...@users.sf.net> http://Nicolas.Thiery.name/ -- 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.
