natural numbers latex code example

Example 1: natural numbers latex

\usepackage{amssymb}
$\mathbb{N}$

Example 2: integer number latex

\usepackage{amssymb}
$\mathbb{Z}$

Example 3: complex numbers latex

\usepackage{amssymb}
$\mathbb{C}$

Example 4: llatex element of

A\in B % one stroke in middle