Sudoku test $$\begin{array}{||c|c|c||c|c|c||c|c|c||} \hline\hline 1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 & 9 \\ \hline 4 & 5 & 6 & 7 & 8 & 9 & 1 & 2 & 3 \\ \hline 7 & 8 & 9 & 1 & 2 & 3 & 4 & 5 & 6 \\ \hline\hline 2 & 3 & 1 & 5 & 6 & 4 & 8 & 9 & 7 \\ \hline 5 & 6 & 4 & 8 & 9 & 7 & 2 & 3 & 1 \\ \hline 8 & 9 & 7 & 2 & 3 & 1 & 5 & 6 & 4 \\ \hline\hline 3 & 1 & 2 & 6 & 4 & 5 & 9 & 7 & 8 \\ \hline 6 & 4 & 5 & 9 & 7 & 8 & 3 & 1 & 2 \\ \hline 9 & 7 & 8 & 3 & 1 & 2 & 6 & 4 & 5 \\ \hline\hline \end{array}$$

Result: Doesn't work as expected. Actual $\rm\LaTeX$ output of the same code: