# [FOM] consistency of NF?

tf at maths.cam.ac.uk tf at maths.cam.ac.uk
Mon Jun 23 03:58:45 EDT 2014

```On Jun 22 2014, Stephen G Simpson wrote:

>OK Thomas, thank you for that helpful background information.  When
>you have understood the proof, please post something about it on FOM.
>While I don't really understand much about NF, it would be nice to
>know that this long-standing problem has been laid to rest.
>
>By the way, what do you mean by "Randall's proof"?  Has he announced a
>consistency proof for NF?  I must have missed it ....

Oh yes. It's a couple of years old now. He's still tweaking it, which is
why i haven't yet sat down and got properly stuck into it, tho' two of my
Ph.D. students are trying to. By the end of my stint in Boise both Randall
and I should be on top of both proofs.

>
>Best wishes,
>-- Steve
>
>tf at maths.cam.ac.uk writes:
> > Date: 21 Jun 2014 06:29:44 +0100
> >
> > Steve, It's 50-odd pages and i learnt of it only a matter of days ago.
> > Randall has had a quick look at it and will no doubt reply to this
> > query. Jamie Gabbay (he is always Jamie, never Murdoch) is a former
> > student of mine; he has picked up the type theory and NF background -
> > and of course he knows all the FM stuff from his nominal sets work - so
> > it is in principle entirely credible that he should find a consistency
> > proof for NF. I am spending august and september in Boise with Randall
> > and the project is for me to really understand Randall's proof and -
> > now! - for us both to understand Jamie's. Watch This Space.
> >
> > On Jun 21 2014, Stephen G Simpson wrote:
> >
> > >Murdoch Gabbay (http://arxiv.org/abs/1406.4060) has published a proof
> > >of the consistency of NF.  Has anyone here understood and/or checked
> > >the proof?
> > >
> > >Stephen G. Simpson
> > >Professor of Mathematics
> > >Pennsylvania State University
> > >research interests:
> > > mathematial logic, foundations of mathematics
> > >
> > >_______________________________________________
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> > >FOM at cs.nyu.edu
> > >http://www.cs.nyu.edu/mailman/listinfo/fom
> > >
>

```