Re: continuum hypothesis and 0=1



On 2007-03-04, Pierre-Yves.Gaillard@xxxxxxxxxxxxxxx wrote:
What is the "standard model"?

In this context "standard model" refers to the structure of naturals
together with addition, multiplication and the successor function. When
speaking of the truth or falsity of arithmetic statements nothing mysterious
is going on; "Goldbach's conjecture is true", for example, is equivalent to
"every even natural greater than two is the sum of two primes", and so on.
In most contexts qualifying "true" with "in the standard model" is
pointless, since non-standard models, or models at all, are not considered,
and are indeed entirely irrelevant. Non-standard models of arithmetic and
such like are studied in certain specialized and rather marginal branches
of mathematical logic, and in that context explicitly mentioning when we're
dealing with the standard model might be in order.

Are there mathematical statements which have "nothing to do with any
particular set of axioms"?

Most mathematical statements have nothing to do with any particular set of
axioms.

--
Aatu Koskensilta (aatu.koskensilta@xxxxxxxxx)

"Wovon man nicht sprechen kann, daruber muss man schweigen"
- Ludwig Wittgenstein, Tractatus Logico-Philosophicus
.



Relevant Pages

  • Re: doubting successor
    ... > count the primes in each model and see what you get. ... of primes is less than the number of naturals... ... standard model are both aleph_0. ... > the axioms of F (or the corresponding axioms of a system which begins ...
    (sci.logic)
  • Re: Cantor Confusion
    ... You mathematicians have had 100 years of intense nit-picking ... does violence at the least does violence to "common sense" ...if that term can ever be applied in the context of infinite sets. ... of the naturals (each of whose very existence is a physical ... all parts of fairyland must be false in reality. ...
    (sci.math)
  • Re: abundance of irrationals!)
    ... Well then perhaps you should make sure that your remarks are IN context. ... there are also "infinite natural numbers" but he's asking you to make ... > element in the set of finite naturals ...
    (sci.math)
  • Re: practical application of Godels Incompleteness Theorem
    ... Godel's original proofs do NOT require definining 'the standard model ... mathematics. ... regards the naturals as the standard model of arithmetics, ...
    (sci.logic)
  • Re: practical application of Godels Incompleteness Theorem
    ... Godel's original proofs do NOT require definining 'the standard model ... First of all, had Godel not "made use" the notion of the naturals, would ... universal quantifier, so that the universal quantifier maps to the set ...
    (sci.logic)

Loading