        \documentclass[12pt]{standalone}
        \usepackage{amsmath,amssymb,tikz-cd,tikz,braids}

        \begin{document}
        $$

\begin{tikzcd}
    P^i \ar[r] \ar[d] & 0 \ar[r] \ar[d] & \cdots \\
    P^{i+1} \ar[r] & P^{i+2} \ar[r] & \cdots 
\end{tikzcd}
        $$
        \end{document}
