\documentclass[11pt,reqno]{amsart}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\usepackage{amsthm,amsmath,amssymb,mathrsfs}
\usepackage{bbm}
\usepackage[MeX]{polski}
\usepackage[T2A,T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{enumitem}
\usepackage{perpage}
\MakePerPage{footnote}
\usepackage[english,russian,polish]{babel}
\input cyracc.def
\font\tencyr=wncyr10
\def\cyr{\tencyr\cyracc}
\prefixing

\textwidth16cm
\headsep 10pt
\textheight22,1cm
\markboth{}{} \topmargin 0pt
\pagestyle{myheadings} \oddsidemargin 10pt \evensidemargin 10pt

\newtheorem{wni}{Wniosek}
\newtheorem{twi}{Twierdzenie}
\newtheorem{lem}{Lemat}
\newtheorem{pro}{Problem}
\theoremstyle{definition}
\newtheorem{uwa}{Uwaga}
\newtheorem{prz}{Przyk/lad}
\newtheorem{defi}{Definicja}

\newtheorem{corollary}{Wniosek}
\newtheorem{theorem}{Twierdzenie}
\newtheorem{lemma}{Lemat}
\newtheorem{problem}{Problem}
\theoremstyle{definition}
\newtheorem{remark}{Uwaga}
\newtheorem{Definicja}{Definicja}

\newtheorem{Thm}{Theorem}
\newtheorem{Lem}[Thm]{Lemma}
\newtheorem{Cor}[Thm]{Corollary}
\newtheorem{Pro}[Thm]{Proposition}
\newtheorem{Obs}[Thm]{Observation}
\newtheorem{Exa}[Thm]{Example}
\theoremstyle{remark}
\newtheorem{Rem}[Thm]{\bfseries Remark}
\theoremstyle{definition}
\newtheorem{Def}[Thm]{Definition}

\numberwithin{equation}{section}

\let\Bbb=\mathbb
\let\Cal=\mathcal
\let\Mbf=\mathbf

\begin{document}

\setcounter{page}{1}

\begin{center}

{\sc\large Jan KOWALSKI }\vskip0.3cm

{\it Uniwersytet {\rm(Miasto)}}\vskip0.45cm

{\bf\large Tytu/l}

\end{center}

\vskip0.4cm

Tekst

\noindent{\bf Twierdzenie.} {\it tekst.}

\smallskip

\noindent{\bf Uwaga.} tekst.

\smallskip

\noindent{\bf Wniosek.} {\it tekst.}

\begin{thebibliography}{9}

\bibitem{Mac1963} T. H. MacGregor, \emph{The radius of univalence of certain analytic functions}, Proc. Amer. Math. Soc. {\bf 14} (1963), no. 3, 514--520.

\bibitem{Pom1975} C. Pommerenke, {\it Univalent Functions}, Vandenhoeck \& Ruprecht, G{\"o}ttingen, 1975.

\bibitem{Rob1936} M. S. Robertson, \emph{On the theory of univalent functions}, Ann. Math. {\bf 37} (1936), 374--408.

\end{thebibliography}








\end{document}