On 7/20/07, Franz Lehner wrote:
here is an algebra question for a change.
I need a version of MonoidRing for MonoidWithZero.
That is, the monoid has a "zero" element which also becomes the zero
element of its monoid ring and thus needs special treatment.
For this I need (so I think) both a Category MonoidWithZero, which is
easy, and a special version of MonoidRing which knows how to treat the zero
element. I would like to reuse as much as possible from MonoidRing,
however I realized that MonoidRingCategory is only locally defined in
mring.spad:
MonoidRing(R: Ring, M: Monoid): MRcategory == MRdefinition where
Term ==> Record(coef: R, monom: M)
MRcategory ==> Join(Ring, RetractableTo M, RetractableTo R) with
...
Is there a smart way to reuse this without completely rewriting it?
I think the short answer is "no". But if you do re-write it, I can see
no reason why this should not be written as a normal category
definition and used in MonoidRing instead of the local macro
definition.
On the other hand perhaps the category "AbelianMonoidRing" in
'src/algebra/polycat.spad.pamphlet' is what you need?
Regards,
Bill Page.
_______________________________________________
Axiom-developer mailing list
Axiom-developer@nongnu.org
http://lists.nongnu.org/mailman/listinfo/axiom-developer
