- #1

- 1,170

- 3

## Homework Statement

Proove that Nx{0} is countable. x stand for a product i.e. like the cartesian product NxN

## Homework Equations

N is countable.

## The Attempt at a Solution

This is so obvious since Nx{0} is just (1,0),(2,0) etc. But how do you write a proof formally?