Sujet : Re: Do you trust Cantor's set/infinity theory?
De : wyniijj5 (at) *nospam* gmail.com (wij)
Groupes : comp.theoryDate : 14. Apr 2025, 17:15:52
Autres entêtes
Organisation : A noiseless patient Spider
Message-ID : <7b47298fc967459d0f9900e3b95fa4029724fae8.camel@gmail.com>
References : 1
User-Agent : Evolution 3.54.3 (3.54.3-1.fc41)
On Mon, 2025-04-14 at 23:39 +0800, wij wrote:
https://sourceforge.net/projects/cscall/files/MisFiles/RealNumber2-en.txt/download
Theorem 7: For a set S of infinite symbols (with finite symbol length), if the
symbols in S can be sorted and have a 'smallest' element symbol, then S
can correspond 1-1 to the elements of the natural number set.
Example1: There is a 1-1 correspondence between integers and
natural numbers, because integer elements can be arranged as 0, 1,
-1, 2, -2, ... Similar to the above example, two-dimensional
numbers (p, q), fractions (p/q), etc. can be sorted by p*∞+q (the
smallest is 0).
Example2: Suppose S contains O(2^N) elements (or any order), then as
long as the elements of S are sortable (e.g., can be represented by
an array), they can form a 1-1 correspondence with the set of
natural numbers.
....
Note: Real numbers can also be defined as (very intuitive and simple):
EN::= Same as the natural numbers defined by Peano Axioms, but the
numbers (elements) can be infinitely long.
ℝ::= {x| x=p/q or -p/q, q≠0, p,q∈EN }
-------------
Minor changes:
Example2: Suppose S contains O(2^N) elements (or any order), then as
long as the elements of S are sortable (e.g., can be represented by
an array, including 'obsolete real number'), they can form a 1-1
correspondence with the set of natural numbers.