سلام
بستههایی که معرفی کردهاید دو بارو\counterwithout و \counterwithin را تعریف کردهاند. فایل استایل chngcntr.sty را تغییر دادهام و در سوال ضمیمه کردهام.
با انجام این تغییرات شما به صورت زیر است:
\documentclass[12pt]{article}
\usepackage{imathconf2019}
\usepackage{chngcntr}
\begin{document}
\selectlanguage{english}
\begin{center}
%\textbf{\Large \sc Title of the abstract}\\[1ex]
%\textbf{P.~P.~Petrenko${}^1$, Ì.~Smith${}^2$}\\[0.4ex]
${}^1$ Affiliation, City, Country\\[0.4ex] % Information for first author
${}^2$ Affiliation, City, Country\\[0.4ex] % Information for second author
%\textit{name1@domain1.com, name2@domain2.com}
\end{center}
Abstracts can be submitted in one of the conference languages (Ukrainian or English). The maximal length of the abstract is one page. Each participant is allowed to send one abstract only.
The abstract should be prepared in LaTex (as a LaTeX-file) and carefully checked for misprints.
It must not include automatic numbering and automatic links to formulas, theorems, article, etc. Please do not use your own macros and do not include pictures in the abstract.
The file should be named using surnames of first two authors (e.g., Petrenko-Smith.tex)
%\textbf{Please do not edit the style file \emph{imathconf2019.sty}.}
The Organizing Committee are kindly requested the authors to use the following examples for the environments and references.
Numbered equation
$$
x'=Ax. \eqno(1)
$$
Reference to equation~(1).
Environments:
\begin{theorem}
Text of the theorem
$$
x'=Ax+t. \eqno(2)
$$
\end{theorem}
%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{lemma}
Text of the lemma.
\end{lemma}
\begin{definition}
Text of the definition.
\end{definition}
\begin{example}
Text of the example.
\end{example}
\begin{problem}
Text of the problem.
\end{problem}
\begin{corollary}
Text of the corollary.
\end{corollary}
\begin{proposition}
Text of the proposition.
\end{proposition}
\begin{remark}
Text of the remark.
\end{remark}
\begin{algorithm}
Text of the algorithm.
\end{algorithm}
Reference to article or book [1]; the analogue of Theorem 1 was established in [2, p.~121].
The TeX- and PDF-files of the abstract should be sent to {\bf imath.young@gmail.com}\,.
The deadline for the abstract submission is {\bf April 25, 2019}.
\vskip 2mm
{\small\it Acknowledgements}
\vskip 2mm
{\small
\begin{enumerate}
\setlength{\itemsep}{-0.5mm}
%%
\item Petrenko~P.\,P. Title of the article. Journal name, Volume, Number, Pages.
\item Smith~M. Title of book.~--- City: Publisher, Year, Number of pages.
%\item Raievska~I.\,Yu., Raievska~M.\,Yu. Finite nearrings with identity on Miller--Moreno groups.
% Mat. Stud., 2014, 42, No.\,1, 15\,--\,20.
%\item Bluman G.\,W., Cole J.\,D. The general similarity solution of the heat
%equation. J. Math. Mech., 1969, 18, 1025\,--\,1042.
%\item Hormander~L. The Analysis of Linear Partial Differential Operators.~--- Moscow: Mir, 1986, V.1, 464~p.
%\item Courant~R. Partial Differential Equations.~--- New York, London, 1964, 831 p.
\end{enumerate}
}
\end{document}
و قسمتی از خروجی شما با تکلایو 2018 مطابق زیر است:
![enter image description here][1]
موفق باشد.
