Give a one-to-one and onto function from $\mathbb{N} \times \mathbb{N}$ to $\mathbb{N}$
109710
Bijection between $\mathbb N \times \mathbb N$ and $\mathbb N$
80684
Counter example for $(A \times B) \cap (C \times D) = (A \cap C ) \times (B \cap D)$
111348
Show that $\mathrm{S}_{m} \times \mathbb{N}^{m} \rightarrow \mathbb{N}^{m}$ defines an action of $\mathrm{S}_{m}$ on $\mathbb{N}^{m}$
10181
Entire one-to-one functions are linear
81264
Is $[0, 1) \times (0, 1)$ homeomorphic to $(0, 1) × (0, 1)$?
50649
On the existence of a continuous bijection $f\colon [0,1]\to [0,1]\times [0,1]$
148668
How to show $A\times (B\cup C) = (A\times B)\cup (A\times C)$
15733
Show that the cardinality of $\mathbb N$ is the same as the cardinality of $\mathbb N \times \mathbb N$
13398
Prove that the interval $(0, 1)$ and the Cartesian product $(0, 1) \times (0, 1)$ have the same cardinality
49953
Proving that a function from $N\times N$ to $N$ is bijective.
149605
Homeomorphism from $[0,1]\times[0,1]$ to $\overline{D}(0,1)$?
152613
Injection from $\mathbb{N}\to\{0,1\}$ to the set of all monotonic decreasing functions from $\mathbb{N}\to\mathbb{Z}$
24370
Dominos ($2 \times 1$ on $2 \times n$ and on $3 \times 2n$)
109219
How do the sets $\emptyset\times B,\ A\ \times \emptyset, \ \emptyset \times \emptyset $ look like?
91980
Prove that f is one-to-one on D
120094
Prove, that for any A, B, C sets, $A\times (B\setminus C) = (A\times B)\setminus (A\times C)$ is true.
55840
Number of functions from n-element set to {1, 2, …, m}