Martin Rubey wrote:
> Note that one of the most fundamental reasons why the species (AKA combinat)
> project doesn't work well with panAxiom / SPAD, is that functions are treated
> specially in panAxiom / SPAD.
>
> If you can come up with a SPAD-compatible replacement for the construct
>
> SPECIES == (L: LabelType) -> CombinatorialSpecies L;
> Plus(
> F: SPECIES,
> G: SPECIES
> )(L: LabelType): CombinatorialSpecies(L) == add [...]
>
> you shall be praised and I'll stop talking about language semantics from now
> on
> and refer to you instead.
>
Martin, you keep posting this code, but this snippet is meaningless
without telling what your goals are. If the goal is to implement
species theory I would probably start:
SemiRing():Category == ....
SpeciesRingCategory():Category == SemiRing with
-- add extra operations like composition and differential
....
Note: IIUC currently you essentially have one type for labels.
To support nontrivial label types one can add argument to
SpeciesRingCategory.
To put it differently: the snippet alone look obscure to me.
Apparently you (Ralf and Martin) are trying to translate
categorical definition directly to Aldor code. But categorical
definition at least formally operates on classes, so is
directly uncomputable. Choosing representation you throw
out some aspects. It is not clear which aspects you retain.
Also, it would help if you say what combinat can do. Looking
at code I see that it can compute generating functions. It
seems that you also have code to enumerate corresponding sets,
but it is not clear what is the result: if I have species
of permutations can I compose resulting permutations?
--
Waldek Hebisch
[EMAIL PROTECTED]
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