Dear Martin:
Martin Rubey wrote:
> William Sit <[EMAIL PROTECTED]> writes:
> > I assume you want MatroidCat to be the category of all matroids,
>
> No, at least not originally. I wanted MatroidCat be the "category" (in the
> sense of axiom/aldor) of those domains, which represent matroids. I.e.,
Dear William,
I like most of what you have written, but I must oppose against a few
things.
Example 1, Matroids
A "matroid" is a mathematical structure with one very, very important
operation, namely "dualizing" which transforms a given matroid into
another. Thus, one is tempted to have a ca
Hi Bertfried,
Category Matroid
expoerts dual
then
Category GraphMatroid
inherits Matroid
=>modifies dual -> dual= if has planar then dual else error
exports new functionality
thereby, you would demolish the semantics of the dual of Matroid.
I would strongly discourage from using su
Dear William, *
thanks a lot for your answer. I think that you clarified the issue quite a bit,
but I still have to think about it.
A short reply...
William Sit <[EMAIL PROTECTED]> writes:
> > Example 1, Matroids
> >
> > A "matroid" is a mathematical structure with one very, very important
> >
Dear Martin:
Martin Rubey wrote:
> The general case
>
> We have a category A with an operation op: % -> %. However, there are natural
> subdomains of domains of A, which are no longer closed under op.
>
> Can you propose a "natural" hierarchy of categories for this situation? Since
> this occu
On 4 Apr 2006, Martin Rubey wrote:
Hi Martin,
a quite interesting question...
> The general case
>
> We have a category A with an operation op: % -> %. However, there are natural
> subdomains of domains of A, which are no longer closed under op.
>
> Can you propose a "natural" hierarchy of categ
Dear all,
I will first describe my problem with two examples occurring in practice, and
finally try to give a more abstract description. The question is, how to
structure categories in these cases.
Example 1, Matroids
A "matroid" is a mathematical structure with one very, very important
operatio
