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Related papers: An Unusual Proof that the Reals are Uncountable

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We give an infinite number of proofs of Pythagoras theorem.Some can be classified as `self-similar proofs'.

History and Overview · Mathematics 2025-09-04 Gaurav Bhatnagar , Sagar Shrivastava

Based on the structure of Fibonacci sequence, we give a new proof for the irrationality exponents of the Fibonacci real numbers. Moreover, we obtain all the irrationality exponents of the real numbers corresponding to the differences of…

Number Theory · Mathematics 2016-02-02 Ying-jun Guo , Zhi-xiong Wen , Jie-meng Zhang

We present a detailed and elementary construction of the real numbers from the rational numbers a la Bourbaki. The real numbers are defined to be the set of all minimal Cauchy filters in $\mathbb{Q}$ (where the Cauchy condition is defined…

History and Overview · Mathematics 2015-11-06 Ittay Weiss

We highlight some facts about continued fractions of real cubic irrationalities. This may be thought as a small section in a textbook on continued fractions.

Number Theory · Mathematics 2023-11-29 Wadim Zudilin

We apply an inductive argument to three theorems of Cantor on (1) the uncountability of infinite binary sequences, (2) the uncountability of real numbers, and (3) the non-equinumerosity of sets with their powersets. This technique proves…

Logic · Mathematics 2025-10-20 Saeed Salehi

The uncountability of $\mathbb{R}$ is one of its most basic properties, known far outside of mathematics. Cantor's 1874 proof of the uncountability of $\mathbb{R}$ even appears in the very first paper on set theory, i.e. a historical…

Logic · Mathematics 2023-06-26 Sam Sanders

In order to prove irrationality of \sqrt{2} by using only decimal expansions (and not fractions), we develop in detail a model of real numbers based on infinite decimals and arithmetic operations with them.

History and Overview · Mathematics 2009-11-02 Martin Klazar

In which a review of the concept of countability is done in mathematics, subjecting review some of the theorems so far accepted, showing their inconsistency and also taking concrete elements on the countability of all the powers of the set…

General Mathematics · Mathematics 2016-01-07 Denis Martínez Tápanes

In this paper, we prove the number of countable models of a countable supersimple theory is either 1 or infinite. This result is an extension of Lachlan's theorem on a superstable theory.

Rings and Algebras · Mathematics 2009-09-25 Byunghan Kim

We take an argument of G\"odel's from his ground-breaking 1931 paper, generalize it, and examine its validity. The argument in question is this: the sentence $G$ says about itself that it is not provable, and $G$ is indeed not provable;…

Logic · Mathematics 2019-07-02 Kaave Lajevardi , Saeed Salehi

In this paper, we shall prove, for any $m\geq 1$, the existence of an uncountable subset of $U$-numbers of type $\leq m$ (which we called the set of {\it $m$-ultra numbers}) for which there exists uncountably many transcendental analytic…

Number Theory · Mathematics 2014-09-01 Diego Marques , Josimar Ramirez

There are numerous ways to represent real numbers. We may use, e.g., Cauchy sequences, Dedekind cuts, numerical base-10 expansions, numerical base-2 expansions and continued fractions. If we work with full Turing computability, all these…

Logic · Mathematics 2020-03-30 Ivan Georgiev , Lars Kristiansen , Frank Stephan

We construct new models of $ZF$ with an uncountable set of reals that has a unique condensation point. This addresses a question by Sierpi\'{n}ski from 1918.

Logic · Mathematics 2018-12-27 Eilon Bilinsky

Remarks on the Cantor's nondenumerability proof of 1891 that the real numbers are noncountable will be given. By the Cantor's diagonal procedure, it is not possible to build numbers that are different from all numbers in a general assumed…

General Mathematics · Mathematics 2007-05-23 Slavica Vlahovic , Branislav Vlahovic

Recently it was shown that it is undecidable whether a term rewrite system can be proved terminating by a polynomial interpretation in the natural numbers. In this paper we show that this is also the case when restricting the…

Logic in Computer Science · Computer Science 2023-07-28 Fabian Mitterwallner , Aart Middeldorp , René Thiemann

Short nonstandard proofs are given for some results about infinite systems of equations in infinitely many variables.

Logic · Mathematics 2024-05-09 David A. Ross

I'll discuss how Goedel's paradox "This statement is false/unprovable" yields his famous result on the limits of axiomatic reasoning. I'll contrast that with my work, which is based on the paradox of "The first uninteresting positive whole…

History and Overview · Mathematics 2007-05-23 G. J. Chaitin

In the present paper, we provide five counterexamples to show directly the Jumarie's formulae are not true for non-differentiable continuous functions.

Classical Analysis and ODEs · Mathematics 2016-11-17 Cheng-shi Liu

This paper is purely expository. We present short elementary proofs of * the Gauss Theorem on constructibility of regular polygons; * the existence of a cubic equation unsolvable in real radicals; * the existence of a quintic equation…

General Mathematics · Mathematics 2026-01-08 A. Skopenkov

In this paper I introduce a new and intuitive first-order foundational theory (where the concept of set is not primitive) and use it to show that the power set of an infinite set does not exist. In particular, proofs of uncountability of a…

Logic · Mathematics 2018-12-04 Eddy El Khalil