\documentclass[12pt]{article}
\usepackage{amsmath,amssymb,color}
\usepackage{tikz-cd}

\title{Commutative Diagrams with TikZ-CD}
\author{Someone's Name}
\date{\today}

\begin{document}

\maketitle

Test diagram:

\begin{tikzcd} A\ar{r} & B\\ C\ar{u} & D\end{tikzcd}

\end{document}
