David Bernier <
davi...@videotron.ca> writes:
> On 06/09/2012 03:31 PM, FredJeffries wrote:
>> On May 24, 9:26 am, WM<
mueck...@rz.fh-augsburg.de> wrote:
>
>>> Brouwer'sconstructivism is claimed, by matheologians, to be a
>>> possible, equally recognized alternative. That's wrong. IfBrouweris
>>> right, then matheology is wrong. There is no possible coexistence such
>>> that an intelligent being could choose between them.
>>>
>>> At least after my proofs there is, for correct mathematics, no longer
>>> the liberty of chosing this or that set of axioms. ZFC is in
>>> contradiction with mathematics.
>>>
>>> And alreadyBrouwerdid not mean to devise an "alternative", but he
>>> knew, Cantor is wrong: "De tweede getalklasse van Cantor bestaat
>>> niet".
>>>
>> <quote>
>> The Brouwer-Hilbert debate
>> was unnecessary because both parties shared a common misconception:
>> that Brouwer’s intuitionism was a restriction of classical
>> mathematics.
In that any intuitionistic proof is also a classical proof,
presumably.
>> But Godel showed in a short paper, published two years after his
>> epochmaking
>> incompleteness theorem of 1931, that it is actually an extension
>> of classical mathematics. At least, this is true for arithmetic (or
>> number
>> theory), but the less said about intuitionistic analysis the better.
In that there is an ionterpretation of classical arithmetic in classical
arithmetic via the double negation translation (for arithmetic),
ie treating classical formulae as meaning something other
than what they say up front, as far as the intuitionistic reading goes.
>> In the light of Godel’s result, we can say that what Brouwer really
>> did was extend classical mathematics by the creation of two new
>> logical
>> operators: the constructive there exists and the constructive or,
>> stronger
>> than their classical counterparts.
And the constructive implication ...
>> Unfortunately for clarity and
>> civility,
>> Godel’s paper did not receive the proper attention or interpretation,
>> and
>> the unseemly squabble dragged on.
>> </quote>
>>
>> Ed Nelson, "Confessions of an Apostate Mathematician", p5
>>
https://web.math.princeton.edu/~nelson/papers/rome.pdf
>
> If we look at the sequence a_n = cos(n!), n >= 0, we get a
> bounded sequence in [-1, 1]. So, this sequence has
> a convergent sub-sequence. Or, there exists a D in [-1, 1]
> such that for any epsilon>0, and any natural number K, there is
> an 'm' with m > K such that: | a_m - D | < epsilon .
>
> There's a mixture of "for all" and "there exists" quantifiers
> there. How would a constructive Q meaning
> Exists: ForAll: ForAll: Exists: P(variables)
> based on the "Exists D" sentence appear, roughly? (refering to Q?)
Q does not talk about cosine, or real numbers at all.
But in general there are two answers: take the statement literally, in
which case it means coming up with a witness term for the D, and an
effective function for m as a function of k, and also for the modulus of
convergence (a_m as a function of m), such that the condition holds.
Alternatively, look at the double negation of the statement,
by replacing "some x. P x" with "not (all x. not (P x))" --
the order relation over reals needs attention also.
> David Bernier
>
--
Alan Smaill