Konvexní analýza
Damn this is nice
$\begin{cases}1 & 2 & 4 \ 2 & 3000 & 4\end{cases}$
or $$ \{ a + n\} \& { a + n} \ { a + n} \text{ and } { a + n} $$
$\left( a \right)$
$\xdef\scal#1#2{\langle #1, #2 \rangle}\xdef\and{\&}\xdef\brackets#1{\left\{ #1 \right\}}$ $\scal a b \and \brackets{ this si okay }$
and $x^*$
$$ \begin{pmatrix} 1 & 2 \ 3 & 4 \end{pmatrix} $$