From: spudnik on
I agree with the above pundits;
all you have to do is actually create such a proof, or
you can just "work-through" any that were done,
such as Fermat's -- http://wlym.com --
the creator of the modern theory of numbers,
of which Godel was a rather crude arithmetical usage
-- totally elementary, but rather laborious --
I think. in particular,
Fermat's "reconstruction" of Euclid's "porisms" is supposed
to be exmplary, for a cannonical geometrical proof.

> Beware of bugs in the above code; I have only proved it correct, not
> tried it. -- Donald E. Knuth

thus:
bada-ba-BOOM -- hey!

> The division sequence repeats the group between A to B,
> giving a quotient of 000 111 000 111 000 111 000...,
> which at no point has a remainder of 0. So 1001 does
> *not* divide 111...111 evenly.

thus:
first of all, did anyone point out that the Archimedean valuation
of "irony" is perhaps a definition of some other (English) word?...
I invite others to supply a better word to his putative de-finite-ion!

I would, again -- at the risk of contributing to any royalties
that AP gets for any one attending to his **** -- like,
to refer to Ore's _Number Theory and Its History_
for a de-finite-ive account of Stevin's revolution
of _The Decimals_, and the reference to it in Munk's treatise
(published by a "vanity press," as he had used
during the Great Depression to publish the first "layman's" account
of aerodynamics.) [am I recalling correctly,
taht this caused the Plutonium One to issue a threat
upon my life -- very scarey ?-]

> You really should read the articles you quote from.

thus:
(1) is not self-consistent?

how does it materially differ from Gauss's arithmetical series,
prime_number + 2n, or what ever?

--l'OEuvre!
http://wlym.com
From: David C. Ullrich on
On Tue, 19 Jan 2010 13:05:39 -0800 (PST), KevinSimonson
<kvnsmnsn(a)hotmail.com> wrote:

>When I was exposed to math in highschool, I was taught that one way to
>prove something was to assume the opposite of that something and then
>derive conclusions from that opposite. If I ever arrived at a
>conclusion that I knew was false, then that would prove the something
>I started out with. This was known as proof by contradiction.
>
>So there is a branch of math, a formal system, I think I can say,
>where one can use proof by contradiction to come up with theorems.
>And I think it's fairly safe to say that this formal system is very
>much in use.
>
>Isn't it true that the consistency of this formal system comes down to
>the assertion that it's not possible to prove a false statement, using
>this system's axioms and rules of inference? I think it is true.
>Then I will assume the opposite of consistency of this formal system.
>I assume that it _is_ possible to prove a false statement, using this
>system's axioms and rules of inference. So I _apply_ that proof, and
>conclude the false statement. Since my conclusion is false, I have
>proven by contradiction that this formal system is consistent.
>
>But I've proven it's consistent within the formal system itself, which
>Kurt Godel proved couldn't be done for a consistent formal system, so
>this system must _not_ be consistent.
>
>Can anybody see the flaw in this argument? Have I _really proved_
>that the math used by the majority of the world is actually
>inconsistent? I'm curious to see what everybody else thinks of this.

Most of the replies so far point out things like for example the
definition of "inconsistent" you're using is not right. This is true,
but missing the point - if we insert the correct definition we still
get something that appears to be a proof that "the formal
system" is inconsistent; we should really be considering why
the corrected version is wrong.

Ok. Say T is "the formal system". Assume that T is not
connsistent.

(*) Then T proves "P and not P" for some P.

Contradition, so T must be consistent (which then
contradicts Godel as you point out).

No, (*) is not a contradiction. (*) is not "P and not P",
(*) just says that T implies P and not P.

Q: But T is "the formal system" used in math, so (*) shows
that P and not P is a theorem of standard math!

A: No. We haven't shown that T implies P and not P.
We've just shown that _if_ T is inconsistent then (*)
holds. To deduce what you deduce from this you need
to _also_ make the assuumption that T is inconsistent,
and that's not part of "stanard math."

>Kevin Simonson
>
>"You'll never get to heaven, or even to LA,
>if you don't believe there's a way."
>from _Why Not_

From: Don Stockbauer on
On Jan 19, 3:38 pm, "Mr. Wymore" <wym...(a)ymail.com> wrote:
> Proof by contradiction is valid:http://mathworld.wolfram.com/ProofbyContradiction.html
>
> Godel showed that there was no way to prove ALL of math was true.  Any
> part of it can be proven by this or other methods.
>
> He also showed that math can be made to contradict itself.  Here's a
> cool book that explains it:http://www.amazon.com/Godel-Escher-Bach-Eternal-Golden/dp/0465026567

Is it available in paperback?
From: g.resta on

> > He also showed that math can be made to contradict itself.  Here's a
> > cool book that explains it:http://www.amazon.com/Godel-Escher-Bach-Eternal-Golden/dp/0465026567
>
> Is it available in paperback?

If you follow the link above you will see that it is available
as paperback and also as used paperback starting from about seven
dollars.

g.
From: Don Stockbauer on
On Jan 20, 8:42 am, "g.re...(a)iit.cnr.it" <g.re...(a)iit.cnr.it> wrote:
> > > He also showed that math can be made to contradict itself.  Here's a
> > > cool book that explains it:http://www.amazon.com/Godel-Escher-Bach-Eternal-Golden/dp/0465026567
>
> > Is it available in paperback?
>
> If you follow the link above you will see that it is available
> as paperback and also as used paperback starting from about seven
> dollars.
>
> g.

Thank you so much. I'll have to get a copy of it and expose myself to
Hofstadter's mindset.