A-E

P-T

$\mathbb{R}$

• $\mathbb{R}$ denotes the set of real numbers

Symbols

$\in$

• $\in$ denotes set membership - we write $x \in X$ if $x$ is an element of the set $X$.

$\setminus$

• $\setminus$ denotes set difference.

$\{a\}$

• $\{a\}$ denotes the set with the unique element $a$.