Help:MathTestHline

$\overline{)\begin{array}{ccc}a& b& S\\ 0& 0& 1\\ 0& 1& 1\\ 1& 0& 1\\ 1& 1& 0\end{array}}$

${\begin{array}{|c|c||c|}a&b&S\\\hline 0&0&1\\0&1&1\\1&0&1\\\hline 1&1&0\\\hline \end{array}}$