Re: FOL/HOL: is there a middle ground?
Date: 19 Jul 2004 17:00:05 -0700
Message-ID: <3638acfd.0407191600.411bb49f_at_posting.google.com>
"Marshall Spight" <mspight_at_dnai.com> wrote in message news:<ZqIKc.113980$MB3.14356@attbi_s04>...
> > Actually, all I want is relation-valued attributes and list-valued > attributes.
I can understand why you'd want list-valued attributes. Speaking as a logic programmer, it's not clear to me why modern DBMS don't come with strong, expressive, statically checked type systems for attributes. For instance, being able to define a `maybe' type would solve all those problems with NULLs right off the bat.
But I still don't understand *why* you'd want relation-valued attributes
if you're going to restrict yourself to finite relations. Surely you
could get most of that functionality using names. For example:
binop A B AopB
"or" F F F
"or" F T T
"or" T F T
"or" T T T
"and" F F F
"and" F T F
"and" T F F
"and" T T T
"xor" F F F
"xor" F T T
"xor" T F T
"xor" T T F
- Ralph