theorem

\documentclass[a4paper]{article}
\usepackage{amsmath}

\begin{document}

Suppose you want to publish something that is as simple as
\begin{align}
     1 + 1 = 2
\end{align}

This is not very impressive. If you want your article to be accepted by IEEE reviewers,
you have to be more abstract. So, you could complicate the left hand side of the expression
by using

\begin{align*}
1 = ln(e) \; and \; 1 = sin^2 x + cos^2 x
\end{align*}

The right hand side can be stated as
\begin{align*}
    2 = \sum_{n=0}^{\infty}\frac{1}{2^n}
\end{align*}

Therefore, Eq.(1) can be expressed more ``scientifically`` as:
\begin{align}
    ln(e)+(sin^2 x + cos^2 x) = \sum_{n=0}^{\infty}\frac{1}{x^n}
\end{align}

which is far more impressive. However, you should not stop here. The expression
can be further complicated by using
\begin{align*}
    1 = cosh(y)\sqrt{1 - tanh^2 y} \; and \; e = \lim_{z \rightarrow 0}{(1 + \frac{1}{z})}^z
\end{align*}

Eq. (2) may therefore be written as
\begin{align}
    ln \left[ \lim_{z \rightarrow 0} (1 + \frac{1}{z})^z \right ] + (sin^2 x + cos^2 x) = \sum_{n=0}^{\infty} \frac{cosh(y \sqrt{1 - tanh^2 y})}{2^n}
\end{align}


\end{document}