When you put two \hline in a latex table it separates it in two different blocks. I want to make that, but in the vertical direction I have tried putting in the tabular options{|c||cccc|} but this doesn't work beause horizontal lines cross the entire table without leaving a blanck between the first and second column.
My table is as follows.
\begin{table}[]
\centering
\begin{tabular}{|c||ccccccccc|}
\hline
r,s & 0&1& 2&3&4&5&6&7&8 \\ \hline \hline
0& 1&$\R\oplus \R$ & $\R(2)$ & $\C(2)$&$\H(2)$&$\H(2)\oplus\H(2)$&$\H(4)$&$\H(4)\oplus\H(4)$&$\R(16)$\\
\hline
\end{tabular}
\caption{Caption}
\label{tab:my_label}
\end{table}
||
and then use\hhline
from the package of that name if you don't want the hlines to cross.\R, \C, \H
?\mathbb{R}
and so on... very popular new commands for math papers.... lol\H
is a very bad idea for that purpose because it is already defined, this could make bibliographies entertaining