What & How & Why

这是本文档旧的修订版！

<Code:tex linenums:1 |Example #1 Our first PHP script: hello.php> \begin{equation} \label{eu_eqn} e^{\pi i} + 1 = 0 \end{equation}

The beautiful equation \ref{eu_eqn} is known as the Euler equation </Code>