Things like \Large R_B
(as seen in your error message) are only possible in math mode. Write instead
\Large $R_B$
and {\Large R_C}
needs no {...}
Write it as \Large $R_C$
and so on. Everything inside a tabular cell is local. And if your whole tabular should be written with the \Large
setting use:
{\Large
\begin{tabular}{...}
...
\end{tabular}\par}
If you have only math expressions in your tabular use
\usepackage{array}
...
\begin{tabular}{>{$}c<{$} ... }
...
\end{tabular}
or use the environment array
instead of tabular
. I both cases you can insert normal text with \text{...}
(amsmath), \textrm{...}
, and/or \mbox{...}
. The first one is the best choice.
In order to fix that, you will have to give the \left\{
its counterpart which would be \right.
on the same line. The second line would need a \left. ... \right\}
.
As you do not need auto-sized brackets here, I would leave it all away.
Here is your example and my version:
% arara: pdflatex
\documentclass{article}
\usepackage{mathtools}
\begin{document}
\begin{align}
R = \left\{(S_1,S_1), (S_1,S_4), (S_4,S_4), (S_4,S_1), (S_2,S_2), (S_2,S_3), (S_3,S_3), (S_3,S_2), (S_0,S_0),\right. \\
\left.(S_0, S_5), (S_5,S_5) , (S_5,S_0)\right\}
\end{align}
\begin{equation}
\begin{split}
R = \{(S_1,S_1), (S_1,S_4), (S_4,S_4), (S_4,S_1), (S_2,S_2), (S_2,S_3), (S_3,S_3),\\ (S_3,S_2), (S_0,S_0), (S_0, S_5), (S_5,S_5) , (S_5,S_0)\}
\end{split}
\end{equation}
\end{document}
And here is a screen-shot of the second version (as the first version exceeds all possible limits...)
Best Answer
In my comment above I have already pointed out what causes the error message. Beyond that, I'm not convinced that you are on the right track. Pure guessing, but I suppose that each of these letter combinations designates some entity that will occur more frequently. To achieve consistent typesetting I suggest to use macros. E.g., you can rewrite your example as follows.
This will give the following output.
To avoid to hard-code the formatting of the chains of identifiers (like putting some space inbetween), you can put the definitions
into the preamble and then just write
instead of