which is exported as


\begin{tabular}{|c|c|c|c|c|c|c|c|c|c|}\hline
% BEGIN RECEIVE ORGTBL fp
Task & C & T & D & Prio & \(S\_{}1\) & \(S\_{}2\) & \(S\_{}3\) & \(S\_{}4\) & \(B\) \\
\hline
\(\tau\_{}1\) & 2 & 8 & 6 & 10 & 1 & 0 & 0 & 0 &  \\
\(\tau\_{}2\) & 4 & 20 & 20 & 8 & 0 & 1 & 1 & 0 &  \\
\(\tau\_{}3\) & 10 & 50 & 40 & 6 & 0 & 0 & 3 & 1 &  \\
\(\tau\_{}4\) & 10 & 100 & 100 & 4 & 2 & 3 & 1 & 0 &  \\
% END RECEIVE ORGTBL fp
\hline
\end{tabular}

which is NOT what I want: the underlines are translated as underlines, and not as subscript command.
 

I also tried the following:

\begin{comment}
#+ORGTBL: SEND fp orgtbl-to-latex :splice t :skip 0 :fmt (6 "$%s$" 7 "$%s$" 8 "$%s$" 9 "$%s$")
| Task     |  C |   T |   D | Prio | S_1 | S_2 | S_3 | S_4 | B |
|----------+----+-----+-----+------+-----+-------+-------+-------+-----|
| $\tau_1$ |  2 |   8 |   6 |   10 |   1 |     0 |     0 |     0 |     |
| $\tau_2$ |  4 |  20 |  20 |    8 |   0 |     1 |     1 |     0 |     |
| $\tau_3$ | 10 |  50 |  40 |    6 |   0 |     0 |     3 |     1 |     |
| $\tau_4$ | 10 | 100 | 100 |    4 |   2 |     3 |     1 |     0 |     |
\end{comment}

and the solution is even worse:

\begin{tabular}{|c|c|c|c|c|c|c|c|c|c|}\hline
% BEGIN RECEIVE ORGTBL fp
Task & C & T & D & $S$\backslash$\(_\)1$ & $S$\backslash$\(_\)2$ & $S$\backslash$\(_\)3$ & $S$\backslash$\(_\)4$ & B \\
...
...
% END RECEIVE ORGTBL fp

\hline
\end{tabular}

Where is the \backslash coming from? I have no idea.

So, where is the problem? How can I put a simple mathematical symbol in a org-mode table?

Thanks in advance

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