# Re: NULLs: theoretical problems?

Date: Fri, 31 Aug 2007 15:21:19 -0000

Message-ID: <1188573679.721764.207130_at_y42g2000hsy.googlegroups.com>

On Aug 31, 2:13 am, Jan Hidders <hidd..._at_gmail.com> wrote:

> On 30 aug, 14:08, JOG <j..._at_cs.nott.ac.uk> wrote:

*>
**>
**>
**> > I use a similar notion to def in my own work, but am lacking any
**> > references for it. You say that it is an established (or at least
**> > recorded) approach - do you have links to texts, or academic
**> > references? Or does it have a more formal nomenclature that I could
**> > search for > my normally leet googling skills are not serving me well.
**>
**> I'm sorry to say that at the moment I cannot tell you where I got it.
**> The thing that comes closest is Beeson's logic of partial terms, which
**> has an explicit definedness operator for terms. But it lacks the idea
**> of a syntactic restriction that allows you to keep the normal
**> reasoning rules of FOL.
*

"The Foundations of Constructive Mathematics" is not an easy book to get hold of...

*>
*

> Btw. while looking for that I did find in comp.theory a list of

*> references on logics dealing with undefinedness. It's probably not
**> useful to you because more than you asked for, but I'm giving it
**> anyway:
**>
**> http://groups.google.com/group/comp.theory/msg/884efa5e74a5f68e
*

thanks for these. Much appreciated.

*>
*

> Of course, if you really want a formal reference I might consider

*> writing a small technical report about it. ;-)
*

*>
*

> Kind regards,

*>
**> -- Jan Hidders
*

Its good to know we've only been thinking about these concepts for 2300 years... Received on Fri Aug 31 2007 - 17:21:19 CEST