On 22 October 2016 at 02:08, oldk1331 <[email protected]> wrote: > Bill, I'm sorry that I give a bad example. > > About the axioms that "map" has to fullfill: > map(id, x) === x for all x > map(f, map(g,x)) === map(compose(f,g), x) for all x, f, g >
Yes, these are the "functor laws" as written in Haskell. > Of course it's possible to have a Functor(E) > for AbelianMonoidRing(R,E), it may not "make sense", > but it is doable, so it is important to have a documentation > for map in each domain that implements it. > Could you provide an example implementation of map for Functor(E) in AbelianMonoidRing? Given that over AbelianMonoidRing there are functions like f(a:R):(% -> %) == (x:%):% +-> a * x I do not see how this is possible. Perhaps I am missing something. -- You received this message because you are subscribed to the Google Groups "FriCAS - computer algebra system" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/fricas-devel. For more options, visit https://groups.google.com/d/optout.
