On Fri, Oct 28, 2011 at 9:10 AM, Jalaluddin Morris wrote: > > Isn't a list more free form and potentially heterogeneous than a product? >
No, in FriCAS List X is homogenous in X. Similarly Tuple X. The only heterogeneous basic types in FriCAS are Record(A:X,B:Y, ...) and Union(A:X, B:Y, ... ) or Union(X,Y, ... ) where A, B, etc. are "labels" or tags. The related Aldor language has Cross(X,Y, ... ) which is like an unlabeled Record type. The labels are like names for the associated projection (or injection) functions. The thing I always found odd was that Axiom and all it's derivatives define the type of a function as Mapping(X,Y, Z, ...) or equivalently (Y,Z, ... ) -> X but fail to give a name to the domain (left hand side) of such functions. Clearly the left hand side is a (cross) product. Regards, Bill Page. -- 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.
