Macros
% Abstracts must be prepared in \LaTeX \ and according to the
% following scheme:
\documentclass[a4paper,11pt]{amsart}
\usepackage{amsmath,amssymb,euscript,amsthm,amsfonts}
%%%%%%%%%%%%%%%%%%%%%%%%%%
\textwidth=13cm \textheight=20cm \pagestyle{myheadings}
\newtheorem{lem}{Lemma}
\newtheorem{thm}{Theorem}
\theoremstyle{definition}
\newtheorem{defn}{Definition}
\theoremstyle{remark}
\newtheorem{remk}{Remark}
\newtheorem{expl}{Example}
\begin{document}
\renewcommand{\proofname}{Proof}
\makeatletter \headsep 10 mm \footskip 10 mm
\begin{center}
{\Large\bf Title }
\end{center}
\vskip 15pt
\begin{center}
First Name(s) and SURNAME(S) of the Author(s)\ (\it{Country})
\end{center}
\vskip 15pt
%In the body text of the paper, please, use the following macros for
%the lemmas, theorems, definitions, remarks, etc.:
\begin{defn}
Statement of definition
\end{defn}
\begin{lem}
Statement of Lemma
\end{lem}
\begin{proof}
Lemma's proof
\end{proof}
\begin{thm}
Statement of Theorem
\end{thm}
\begin{proof}
Theorem's proof
\end{proof}
\begin{remk}
Statement of remark
\end{remk}
\vskip 15 pt
%References should be given in the following way:
\begin{thebibliography}{99}
\small
\bibitem{1} Author(s) \ \ (date of publication), {\it Title}, Title
of the periodical, {\bf Volume}, number, pages (via hyphen).
\bibitem{2} Author(s) \ \ (date of publication),
{\it Title}. -- City: Publisher. Number of pagess.
\end{thebibliography}
\vskip 20 pt
\centerline{\large Example}
\begin{thebibliography}{99}
\small
\bibitem{1} E.B. Dynkin \ \ (2004)
{\it On upper bounds for positive
solutions of semilinear equations}, J. Funct. Anal., {\bf 210},
no. 1, 73--100.
\bibitem{2} I.I. Gikhman, A.V.Skorokhod \ \ (2004)
{\it The theory of stochastic processes. II}. -- Berlin,
Springer-Verlag, viii+441 pp.
\end{thebibliography}
%At the end of the paper the following information should be
%provided:
\vskip 20 pt
\noindent {\it Affiliation(s) of the author(s) }
\vskip 2 pt
\noindent {\it e-mail: {\tt ...... @..........}}
\end{document}