On Tue, Jul 8, 2008 at 7:46 PM, Gabriel Dos Reis wrote: > On Tue, Jul 8, 2008 at 6:29 PM, Bill Page wrote: > >> Categories are values of the domain Category, so the domain Category >> is the domain of subdomains of Domain. Category is like a power set >> object in category theory. > > I think I may be persuaded on this, except that I'm still unclear whether > I appreciate sufficiently the notion of `subdomain', which for me is still > a bit of mystery. >
It seems less mysterious to me. I think almost: Category():Domain == SubDomain Domain 'SubDomain' is like the domain constructor 'Set' except of course unlike 'Set Domain', on coerce to OutputForm the objects of 'Category' have names (the category name). But the result of 'members' would be List(Domain): members: % -> List Domain implemented by a database query. One might also expect more reflections such as: exports: % -> List Record(name:Symbol, body:Tuple Domain -> Domain) parents: % -> List % etc. Regards, Bill Page. ------------------------------------------------------------------------- Sponsored by: SourceForge.net Community Choice Awards: VOTE NOW! Studies have shown that voting for your favorite open source project, along with a healthy diet, reduces your potential for chronic lameness and boredom. Vote Now at http://www.sourceforge.net/community/cca08 _______________________________________________ open-axiom-devel mailing list open-axiom-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/open-axiom-devel
