Waldek Hebisch <[EMAIL PROTECTED]> writes: > Hmm, I still do not understand how species work but my impression was that:
> 1) species lack much of functionality present in concrete domains > 2) species impose serious overhead compared to specialized domains Sorry, I miscommunicated - as Ralf already pointed out. The idea is only to use Species as a good "Category" (warning: SPAD meaning) framework, because mathematically convincing. More concretely: the domain Permutation(S: SetCategory) should stay! But, it should export SpeciesCategory S, in particular: structures: Set S -> Stream % ++ structures s returns all permutations of the set s and something like structures: (Set S, FiniteGroup S) -> Stream % ++ structures(s, g) returns all isomorphismtypes of permutations of the set s ++ under the action of g The domain SetOfMIntegersInOneToN should be generalised and renamed into Combination(n: NNI, S: SetCategory) The package PartitionsAndPermutations should go away. It's functionality should be moved into the two domains Partition (or possibly SetPartition) and Permutation. Aggregates would also export SpeciesCategory, of course. I'm not completely sure yet how to provide the domains of the isotypes, eg. Partition vs SetPartition. We could either have two domains, or one (in this case SetPartition), that is able to "produce" the other. I believe it's easier to have two. So, there is *no* overhead. Only for experimentation one would generate a species using Plus, Times, Compose, etc. However, without turning Permutation, Combination, etc. into Species, experimentation is difficult. I hope this is clearer now. There is a showstopper currently. I need to have the problems (with the special operation coerce) pointed out in the beginning of this thread, fixed. I hope this is possible. Martin --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "FriCAS - computer algebra system" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/fricas-devel?hl=en -~----------~----~----~----~------~----~------~--~---
