On Thu, Feb 7, 2013 at 4:30 PM, Karen Coyle <[log in to unmask]> wrote:

I'm not sure what the "semantics of 'type'" means in this context, since you do say "defining a new 'type' of work." I think the question becomes: will all combinations of additional properties require defining as a new type (or whatever it is called)?

 From a logical point of view, every distinct combination of properties can be considered to be a distinct class.  Indeed, you can treat everything that has a particular value of a property to be class.  

These classes need not be given names.