## Notation

So as to make any non-mathematicians’ (as well as my own!) life a bit easier,  here are some commonly used symbols and their meanings:

$\mathbb{N}$   The natural numbers (non-negative integers): $0,1,2,3,4,...$

$\mathbb{Z}$   The integers (whole numbers, including negative ones): $...,\text{-}2,\text{-}1,0,1,2,...$

$\mathbb{Q}$   The rational numbers (fractions): $\frac{1}{2},\text{-}\frac{2}{3},\frac{95}{96},$etc.

$\mathbb{R}$   The real numbers (every number with no imaginary part): $0.5,\text{-}5.69,1.33333333,$ etc.

(Note that$\mathbb{N}$ is contained in$\mathbb{Z}$is contained in$\mathbb{Q}$is contained in$\mathbb{R}.)$