Multirow multicolumn combination problem

Question

Okay, so I'm trying to make this sort of a table:

----------------------------
|                  A       |
|     &       true   false |
|           |--------------|
| B | true  |  1       1   |
|   | false |  2       3   |
|--------------------------|

and this is my code.

\begin{tabular}{|cccc|}
\hline
\multicolumn{2}{c}{\multirow{2}{*}{\&}} & & A
 & & true & false
\multirow{2}{*}{B} & false & 0 & 1 \\
 & true & 2 & 3 \\
\hline
\end{tabular}

Idk what I did wrong tbh. I'm finding this multirow, multicolumn stuff a little confusing...

Answer 1

Like this:

\documentclass{article}
\usepackage{multirow}

\begin{document}
\begin{tabular}{cc|cc}
            &           &   \multicolumn{2}{c}{A}   \\
\multicolumn{2}{c|}{\&} &   true    &   false       \\
    \hline
\multirow{2}{*}{B}      &   true    &   1   &    1  \\
                        &   false   &   2   &   3   
\end{tabular}
\end{document}

or this:

\documentclass{article}
\usepackage{multirow}

\begin{document}
\begin{tabular}{cc|cc}
\multicolumn{2}{c}{}    &   \multicolumn{2}{c}{A}   \\
\multicolumn{2}{c|}{\&} &   true    &   false       \\
    \hline
\multirow{2}{*}{B}      &   true    &   1   &   1   \\
            &   false   &   2       &   3           \\
\end{tabular}
\end{document}

or this?

\documentclass{article}
\usepackage{multirow}

\begin{document}
\begin{tabular}{|cc|cc|}
    \hline
\multicolumn{2}{|c|}{}  &   \multicolumn{2}{c|}{A}  \\
\multicolumn{2}{|c|}{\&}&   true    &   false       \\
    \hline
\multirow{2}{*}{B}      &   true    &   1   &   1   \\
            &   false   &   2       &   3           \\
    \hline
\end{tabular}
\end{document}

or finally (as described in your comment below):

\documentclass{article}
\usepackage{multirow}

\begin{document}
\begin{tabular}{|c|c|cc|}
    \hline
\multicolumn{2}{|c|}{}  &   \multicolumn{2}{c|}{A}  \\
    \cline{3-4}
\multicolumn{2}{|c|}{\&}&   true    &   false       \\
    \hline
\multirow{2}{*}{B}      &   true    &   1   &   1   \\
            &   false   &   2       &   3           \\
    \hline
\end{tabular}
\end{document}

to my taste, I would choose the first example ...

Answer 2

Here is a way to do that table with {NiceTabular} of nicematrix.

\documentclass{article}
\usepackage{nicematrix}

\begin{document}

\begin{NiceTabular}{|c|c|cc|}
\Hline
\Block{2-2}{}   &       & \Block{1-2}{A} \\
\Hline
\Block{1-2}{\&} &       & true  & false  \\
\Hline
\Block{2-1}{B}  & true  & 1     & 1      \\
                & false & 2     & 3      \\
\Hline
\end{NiceTabular}

\end{document}