tikzcd align one diagram below another

Question

I want to use tikzcd to draw a diagram with one above another, and with a big downarrow from up to down. So I need to put the following 3 parts vertically: And I want to get another similar one on its right, which I believe I can use \qquad. My code will be like this:

\begin{equation}
\begin{tikzcd}[column sep=3em]
w \ar[rrd, bend left=16] \ar[rd, dotted, "\exists!"'] &  &  \\
&  x  \ar[r, "f"']  &  y
\end{tikzcd}
\begin{tikzcd}[column sep=3em]
    {} \ar[Rightarrow, d, "p"]\\
    {}
\end{tikzcd}
\begin{tikzcd}[column sep=3em]
    p(w) \ar[rrd, bend left=12] \ar[rd]  &  &  \\
    &  p(x)  \ar[r, "p(f)"']        &  p(y)
\end{tikzcd}
\qquad
\begin{tikzcd}[column sep=3em]
w \ar[rrd, bend left=16] \ar[rd, dotted, "\exists!"'] &  &  \\
&  x  \ar[r, "f"']  &  y
\end{tikzcd}
\begin{tikzcd}[column sep=3em]
    {} \ar[Rightarrow, d, "p"]\\
    {}
\end{tikzcd}
\begin{tikzcd}[column sep=3em]
    p(w) \ar[rrd, bend left=12] \ar[rd]  &  &  \\
    &  p(x)  \ar[r, "p(f)"']        &  p(y)
\end{tikzcd}
\end{equation}

The problem is, how to modify my code to get what I want? A way to make the big downarrow bigger would also be welcome. Thanks!

Answer 1

The easiest way to write both diagrams one above the other is probably to use a single tikzcd environment for the first diagram, the arrow and the second diagram.

\documentclass{article}
\usepackage{amsmath}
\usepackage{tikz-cd}
\begin{document}
\begin{equation}
\begin{tikzcd}[column sep=3em]
w \ar[rrd, bend left=16] \ar[rd, dotted, "\exists!"'] &  &  \\
&  x  \ar[r, "f"']  &  y \\[-8mm]
    & {} \ar[Rightarrow, d, "p"]\\[5mm]
    & {} \\[-12mm]
    p(w) \ar[rrd, bend left=12] \ar[rd]  &  &  \\
    &  p(x)  \ar[r, "p(f)"']        &  p(y)
\end{tikzcd}
\hspace*{11mm}
\begin{tikzcd}[column sep=3em]
w \ar[rrd, bend left=16] \ar[rd, dotted, "\exists!"'] &  &  \\
&  x  \ar[r, "f"']  &  y \\[-8mm]
    & {} \ar[Rightarrow, d, "p"]\\[5mm]
    & {} \\[-12mm]
    p(w) \ar[rrd, bend left=12] \ar[rd]  &  &  \\
    &  p(x)  \ar[r, "p(f)"']        &  p(y)
\end{tikzcd}
\end{equation}
\end{document}

Here, I used two environments for the two columns, as it makes the code easier to read. However, if the diagrams you wish to add on the right are different from those on the left, the columns might not be properly aligned. If that is the case, you could fix that by just putting everything in the same tikzcd environment.