for all latex code example
Example 1: itemize latex
\begin{enumerate}
\item The labels consists of sequential numbers.
\item The numbers starts at 1 with every call to the enumerate environment.
\end{enumerate}
Example 2: latex x element of symbol
\documentclass{article}
\usepackage{graphicx}
\usepackage{amsmath}
\newcommand\Inn{%
\mathrel{\ooalign{$\subset$\cr\hfil\scalebox{0.8}[1]{$=$}\hfil\cr}}%
}
\begin{document}
\[
A\in B % one stroke in middle
\]
\[
A\Inn B % two strokes in middle
\]
\end{document}
Example 3: llatex element of
A\in B % one stroke in middle