\documentclass{article}

\usepackage{tikz}
\usepackage{tikz-cd}

\usepackage[active,tightpage]{preview}
\PreviewEnvironment{tikzpicture}
\setlength\PreviewBorder{1mm}%


\begin{document}

\begin{tikzcd}
A_{S}\times\,_{S}B\arrow{rr}{\beta}\arrow{rd}{\tau}&&Y\\&T\arrow{ur}{\beta^{'}}
\end{tikzcd}


\end{document}