\documentclass[a4paper]{article} % kodovanie diakritiky je utf-8
\usepackage{slovak}
\usepackage[utf8x]{inputenc}

\let\eps=\varepsilon % definujeme si pekne epsilon
\let\then=\Rightarrow % krok odvodenia

\def\header#1#2{% definujeme hlavicku ulohy, parametre su nazov a meno cloveka
\centerline{\Large\sc FoJa -- #1}
\medskip
\centerline{\large #2}
\vspace{-\baselineskip}\rightline{\today}
\bigskip\hrule\bigskip

}

\addtocounter{section}{1}
\newtheorem{veta}{Veta}[section]
\newenvironment{dokaz}{\trivlist\item[\hskip \labelsep{\bfseries Dôkaz.}]}{\endtrivlist}

\begin{document} %%%% samotny dokument zacina tu %%%%

\header{Domáca úloha \#0}{Mišo Forišek}

\end{document}
