From: MoeBlee on
On Mar 2, 11:11 pm, Transfer Principle <lwal...(a)lausd.net> wrote:

> Of course, if MoeBlee doesn't even consider PA to be
> adequate for the sciences, what chance does RE (or anyone
> else) have in convincing him that a _weaker_ theory, such
> as an ultrafinitist theory, is adequate for science?

As far as I know, first order PA is not adequate. (I'm open to being
convinced otherwise, though.)

MoeBlee
From: Aatu Koskensilta on
MoeBlee <jazzmobe(a)hotmail.com> writes:

> As far as I know, first order PA is not adequate. (I'm open to being
> convinced otherwise, though.)

Sink your teeth into the mumblings of Feferman on predicativism, ACA_0,
proof-theoretic reductions, what not, then!

--
Aatu Koskensilta (aatu.koskensilta(a)uta.fi)

"Wovon man nicht sprechan kann, dar�ber muss man schweigen"
- Ludwig Wittgenstein, Tractatus Logico-Philosophicus
From: MoeBlee on
On Mar 3, 10:37 am, Aatu Koskensilta <aatu.koskensi...(a)uta.fi> wrote:
> MoeBlee <jazzm...(a)hotmail.com> writes:
> > As far as I know, first order PA is not adequate. (I'm open to being
> > convinced otherwise, though.)
>
> Sink your teeth into the mumblings of Feferman on predicativism, ACA_0,
> proof-theoretic reductions, what not, then!

But isn't ACA_0 a theory not compatible in strength with PA rather
than a theory weaker or equal to PA?

MoeBlee

From: MoeBlee on
On Mar 3, 10:41 am, MoeBlee <jazzm...(a)hotmail.com> wrote:
> compatible

I meant 'comparable'.

MoeBlee
From: Aatu Koskensilta on
MoeBlee <jazzmobe(a)hotmail.com> writes:

> But isn't ACA_0 a theory not compatible in strength with PA rather
> than a theory weaker or equal to PA?

Nope. ACA_0 aka elementary analysis is a conservative extension of PA.

--
Aatu Koskensilta (aatu.koskensilta(a)uta.fi)

"Wovon man nicht sprechan kann, dar�ber muss man schweigen"
- Ludwig Wittgenstein, Tractatus Logico-Philosophicus