I would like to ask some hints towards the proof that The set of countable sets in $\mathbb{R}$ is equinumerous to the set $\mathbb{R}$
2026-04-06 03:19:27.1775445567
the set of countable sets of Real numbers
959 Views Asked by Bumbble Comm https://math.techqa.club/user/bumbble-comm/detail At
1
There are 1 best solutions below
Related Questions in SET-THEORY
- Theorems in MK would imply theorems in ZFC
- What formula proved in MK or Godel Incompleteness theorem
- Proving the schema of separation from replacement
- Understanding the Axiom of Replacement
- Ordinals and cardinals in ETCS set axiomatic
- Minimal model over forcing iteration
- How can I prove that the collection of all (class-)function from a proper class A to a class B is empty?
- max of limit cardinals smaller than a successor cardinal bigger than $\aleph_\omega$
- Canonical choice of many elements not contained in a set
- Non-standard axioms + ZF and rest of math
Related Questions in CARDINALS
- Ordinals and cardinals in ETCS set axiomatic
- max of limit cardinals smaller than a successor cardinal bigger than $\aleph_\omega$
- If $\kappa$ is a regular cardinal then $\kappa^{<\kappa} = \max\{\kappa, 2^{<\kappa}\}$
- Intuition regarding: $\kappa^{+}=|\{\kappa\leq\alpha\lt \kappa^{+}\}|$
- On finding enough rationals (countable) to fill the uncountable number of intervals between the irrationals.
- Is the set of cardinalities totally ordered?
- Show that $n+\aleph_0=\aleph_0$
- $COF(\lambda)$ is stationary in $k$, where $\lambda < k$ is regular.
- What is the cardinality of a set of all points on a line?
- Better way to define this bijection [0,1) to (0,1)
Trending Questions
- Induction on the number of equations
- How to convince a math teacher of this simple and obvious fact?
- Find $E[XY|Y+Z=1 ]$
- Refuting the Anti-Cantor Cranks
- What are imaginary numbers?
- Determine the adjoint of $\tilde Q(x)$ for $\tilde Q(x)u:=(Qu)(x)$ where $Q:U→L^2(Ω,ℝ^d$ is a Hilbert-Schmidt operator and $U$ is a Hilbert space
- Why does this innovative method of subtraction from a third grader always work?
- How do we know that the number $1$ is not equal to the number $-1$?
- What are the Implications of having VΩ as a model for a theory?
- Defining a Galois Field based on primitive element versus polynomial?
- Can't find the relationship between two columns of numbers. Please Help
- Is computer science a branch of mathematics?
- Is there a bijection of $\mathbb{R}^n$ with itself such that the forward map is connected but the inverse is not?
- Identification of a quadrilateral as a trapezoid, rectangle, or square
- Generator of inertia group in function field extension
Popular # Hahtags
second-order-logic
numerical-methods
puzzle
logic
probability
number-theory
winding-number
real-analysis
integration
calculus
complex-analysis
sequences-and-series
proof-writing
set-theory
functions
homotopy-theory
elementary-number-theory
ordinary-differential-equations
circles
derivatives
game-theory
definite-integrals
elementary-set-theory
limits
multivariable-calculus
geometry
algebraic-number-theory
proof-verification
partial-derivative
algebra-precalculus
Popular Questions
- What is the integral of 1/x?
- How many squares actually ARE in this picture? Is this a trick question with no right answer?
- Is a matrix multiplied with its transpose something special?
- What is the difference between independent and mutually exclusive events?
- Visually stunning math concepts which are easy to explain
- taylor series of $\ln(1+x)$?
- How to tell if a set of vectors spans a space?
- Calculus question taking derivative to find horizontal tangent line
- How to determine if a function is one-to-one?
- Determine if vectors are linearly independent
- What does it mean to have a determinant equal to zero?
- Is this Batman equation for real?
- How to find perpendicular vector to another vector?
- How to find mean and median from histogram
- How many sides does a circle have?
Hint: $\Bbb{R^N\sim(N^N)^N\sim N^{N\times N}\sim N^N}$. Show that there exists a surjection from that set onto the set of countable subsets and use the axiom of choice to conclude there is an injection in the reverse direction.
Note that the axiom of choice has to be used, it is consistent that the axiom of choice fails and there is no bijection between the two sets (but there is still a surjection as above)!