Show that the cardinality of $\mathbb N$ is the same as the cardinality of $\mathbb N \times \mathbb N$
6161
The cartesian product $\mathbb{N} \times \mathbb{N}$ is countable
146436
Cardinality of the set of bijective functions on $\mathbb{N}$?
70861
$\mathbb P^n\times \mathbb P^m\not\cong \mathbb P^{m+n}$
71133
prove inequlity about cardinality power sets
149673
Cardinality of an infinite union of finite sets
71967
cardinality of the set of $ \varphi: \mathbb N \to \mathbb N$ such that $\varphi$ is an increasing sequence
149382
Prove that $(0,1) \subseteq\mathbb R$ and $(4,10) \subseteq\mathbb R$ have the same cardinality.
54406
Is $\mathbb Q \times \mathbb Q $ a denumerable set?
89167
Cardinality of equivalence relations in $\mathbb{N}$
106325
Question about Cardinality
148668
How to show $A\times (B\cup C) = (A\times B)\cup (A\times C)$
64656
how do you prove that $A\times (B\setminus C) = (A\times B) \setminus (A\times C)$?
86263
How do we show there are the same number of elements in each of the sets?
109054
Given an infinite set of cardinality $X$, is there a chain in $\mathcal P(X)$ of the same cardinalty of $\mathcal P(X)$?
109764
Find the cardinality of the quotient of $\mathbb R$ in respect to R
109710
Bijection between $\mathbb N \times \mathbb N$ and $\mathbb N$
144787
Show that the set of all infinite subsets of $\mathbb{N}$ has cardinality greater than $\mathbb{N}$