New post in Elementary-set-theory

Decide whether the set A of positive integers divisible by 17 and B the set of positive integers divisible by 11 are in bijection.

July 26th, 2022

What is countably infinite set?

January 15th, 2023

prove that 2 closed interval sets have equal cardinalities

December 28th, 2022

Prove (0,1) is uncountable (any method)

July 23rd, 2022

Is there an injective function from the set of natural numbers N to the set of rational numbers Q, and viceversa?

August 18th, 2022

How is the set of rational numbers countably infinite?

October 28th, 2022

Which of the following sets are equal?

November 10th, 2022

Suppose each of A,B, and C is a nonempty set. Prove that if (AxB) is a subset of (BxC), then A is a subset of C.

July 23rd, 2022

If $A$ and $B$ are sets, and $A$ is element of $B$

August 14th, 2022

Is an empty set equal to another empty set?

July 22nd, 2022

List the elements of the set

July 31st, 2022

what does this symbol mean (like a perpendicular symbol, in set theory)

July 22nd, 2022

Set theory (A\C) \ (B\C) = (A\B)\C

July 29th, 2022

How to show that $\mathbb Z \times \mathbb Z \times \mathbb Z$ is countable by bijection?

July 29th, 2022

Can I show that two sets are equinumerous by showing a bijection between them?

August 1st, 2022

Showing that a set is countably infinite by defining a bijection between $\Bbb N$ and that set.

November 16th, 2020

Cartesian product of Power Sets

August 1st, 2022

Give a Bijection that is in-between 2 intervals and use a formal proof to show that it is a bijection.

April 3rd, 2020

How to prove that $\mathbb{Z} \times \mathbb{Z}$ is countable.

August 1st, 2022

Is every point of rational number boundary point?

January 25th, 2020

Rational number SAT

May 28th, 2020

Specify a bijection from [0,1] to (0,1].

August 1st, 2022

Is ∅ equivalent to {∅}?

August 1st, 2022

many to one functions

March 25th, 2020

Vector space of infinite sequences in $\Bbb R$

August 1st, 2022

Cartesian product and union

August 1st, 2022

Functions involving infinite set -> infinite set and one-to-one and/or onto

March 23rd, 2020

Show that a relation is equivalent if it is both reflexive and cyclic.

September 27th, 2021

Is the set of real numbers not a subset of the set of whole numbers?

August 1st, 2022

Proving properties of the images and inverse images of functions

July 1st, 2020