There are at least two possible paths toward a category hierarchy in Sage, adopting Axiom's version or designing a new one.
The key advantage of adopting the Axiom category hierarchy is the Sage system could reuse a lot of the algorithms in Axiom. The Spad language used in Axiom is similar in style and spirit to the Sage python language. If the same categories were available it should be possible to use the algorithms in Axiom's domains as written. The temptation to re-design is very seductive but not very productive. ======================================================================== For those who don't understand Axiom's category/domain/package structure I'll give the following very weak analogy: You might find it useful to understand that Axiom has the algebra divided into 3 kinds of things, Categories, Domains, and Packages. By analogy to clothing, Categories would be the patterns, fabrics, buttons, styles and other things that are not specific. Mathematically these are things like OrderedSet which specify functions like >, <=, etc. Domains are instances of choices, like a particular dress, which is chosen from a selection of categories by inheritance, so that a particular domain (dress) has a certain fabric, pattern, style, etc. Mathematically these are domains like Integer which model the integer number system. Packages are tools for dressmaking, such as sewing machines, button-hole makers, ironing boards, etc. In general, you work in domains which are particular instances of mathematics with certain functions and properties inherited from the categories. Every object created lives in some domain. --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---