The file algebra/domain.spad.pamphlet contains this definition:

  )abbrev domain CATEGORY Category
  ++ Author: Gabriel Dos Reis
  ++ Date Create: February 16, 2008.
  ++ Date Last Updated: February 16, 2008.
  ++ Basic Operations: coerce
  ...

but OpenAxiom does not always treat Category this way:

(1) -> )show Category

   The )show system command is used to display information about types 
      or partial types. For example, )show Integer will show 
      information about Integer .

      Category is not the name of a known type constructor. If you want
      to see information about any operations named Category , issue
                        )display operations Category

Category

(1)

x:Category

   There are no library operations named Category 
      Use HyperDoc Browse or issue
                              )what op Category
      to learn if there is any operation containing " Category " in its
      name.

   Cannot find a no-argument definition or library operation named 
      Category .

Category has Category

   There are no library operations named Category 
      Use HyperDoc Browse or issue
                              )what op Category
      to learn if there is any operation containing " Category " in its
      name.

   Cannot find a no-argument definition or library operation named 
      Category .

Axiom Version: => /usr/local/lib/open-axiom/x86_64-unknown-linux/1.2.0-2008-05-25

hat is a regression, because the rest of the compiler and interpreter assumes that Category is conceptually a category -- even when it has a domain implementation.

gdr wrote:

  Category is conceptually a category -- even when it has a domain implementation

Could you please explain what that means? :-)

At the conceptual level, OpenAxiom thinks of Category as a category. The category of categories. However, it has a domain implementation, e.g. as reported by )show. That is just an implementation detail.

OpenAxiom trunk as of 2008-05-29 says this:

 (5) -> Category has Category

   (5)  true
                             Type: Boolean

 (6) -> Domain has Category

   (6)  true
                             Type: Boolean

 (7) -> Category has Type

   (7)  true
                             Type: Boolean

Severity: normal => wishlist