% =====================================================================
% KolKom 2026 — Contributed Talk Abstract Template
%
% 43rd Kolloquium über Kombinatorik
% Berlin, 13–14 November 2026
% https://kolkom26.zib.de
%
% ---------------------------------------------------------------------
%
% Instructions
%   1. Fill in the title, authors, and affiliations below.
%   2. Replace the placeholder in the abstract environment with your
%      short abstract — use the SAME text you enter in the "Abstract"
%      field of the OpenReview submission form.
%   3. Write the extended abstract under \section{Introduction} (and add
%      further \section{...} blocks as needed). Aim for roughly two
%      pages; a bit shorter or longer is fine.
%   4. Replace the sample \bibitem entries with your own references,
%      following the format specified in the REFERENCE FORMAT block.
%   5. Compile with pdflatex (two passes; no biber/bibtex needed) and
%      upload the resulting PDF to the OpenReview submission form. Keep
%      this .tex source — the organisers may ask for it for the program.
%
% Format
%   - Short abstract: one paragraph, identical to the abstract you enter
%     on the OpenReview form.
%   - Extended abstract: roughly two pages (a bit shorter or longer is
%     fine), excluding references.
%   - Use the same presenting author, affiliation, and talk title as on
%     the submission form.
%   - Keep the running header, page size, and margins as they are (for a
%     uniform program); add any packages you need above \begin{document}.
%
% Figures
%   - tikz / pgfplots (or other pure-LaTeX figures) are preferred and
%     keep the source self-contained. External image files are fine too,
%     since you compile and upload the PDF yourself.
%
% Authors and coauthors
%   - One \author{...} per person. List only actual coauthors of the
%     underlying work here. Advisors, funders, and acknowledged
%     collaborators who are not coauthors belong in the optional
%     \section*{Acknowledgements} block at the end of the body, not as
%     \author.
%   - The presenting author is marked via \thanks{...} (see the first
%     \author below).
%   - Affiliations are numbered. Reference them by [1], [2], ... on
%     each author.
%
% Citations
%   - Cite with \cite{key}, e.g. \cite{Sauermann2021}.
%   - The displayed label is the optional argument of \bibitem, e.g.
%     [Sau21], [CGMS23] — first 3 letters of a single author + 2-digit
%     year, or initials of up to 4 authors + 2-digit year.
%
% ---------------------------------------------------------------------
% REFERENCE FORMAT — please follow this exactly:
%
%   Journal article:
%     \bibitem[ABC23]{key}
%     A. Author, B. Other, and C. Third,
%     \emph{Title of the paper},
%     Journal Name \textbf{volume} (year), first--last.
%     \href{https://doi.org/10.xxxx/yyyy}{doi:10.xxxx/yyyy}.
%
%   Preprint:
%     \bibitem[ABC23]{key}
%     A. Author and B. Other,
%     \emph{Title of the preprint},
%     Preprint, 2023.
%     arXiv:\href{https://arxiv.org/abs/2303.09521}{2303.09521}.
%
%   Conference proceedings:
%     \bibitem[ABC23]{key}
%     A. Author and B. Other,
%     \emph{Title of the paper},
%     in: Proceedings of SODA 2023, SIAM, pp. 100--110.
%     \href{https://doi.org/10.xxxx/yyyy}{doi:10.xxxx/yyyy}.
%
%   Book:
%     \bibitem[Aut00]{key}
%     A. Author,
%     \emph{Book Title},
%     Publisher, City, year.
%
%   PhD thesis:
%     \bibitem[Aut20]{key}
%     A. Author,
%     \emph{Thesis title},
%     PhD thesis, Institution, year.
%
%   Conventions:
%     - Authors: initial(s) + last name, comma-separated, "and" before last.
%       List all authors; use "et al." only when there are more than six.
%     - Title: italicised.
%     - Journal: abbreviated per AMS conventions; volume in bold.
%     - Pages: en-dash (--) between first and last.
%     - End every entry with a period.
%     - For DOIs and arXiv IDs, use \href{...}{...} as shown.
%     - If a preprint has been published, cite the published version and
%       optionally append the arXiv ID after the journal reference.
% =====================================================================

\documentclass[11pt,a4paper]{article}

\usepackage[T1]{fontenc}
\usepackage{lmodern}
\usepackage{microtype}
\usepackage{amsmath,amssymb,amsthm,mathtools}
\usepackage[margin=2.5cm]{geometry}
\usepackage{parskip}
\usepackage[affil-it]{authblk}
\usepackage{xcolor}
\usepackage{environ}
\usepackage{fancyhdr}
\usepackage{hyperref}
\hypersetup{hidelinks,colorlinks=false}

% =====================================================================
% KolKom 2026 identification — running header on every page.
% Please do not remove: this marks the PDF as a KolKom 2026 extended
% abstract. (\maketitle forces the plain style on the first page, so the
% header is re-asserted with \thispagestyle{kolkom} after \maketitle.)
% =====================================================================
\setlength{\headheight}{14pt}
\fancypagestyle{kolkom}{%
  \fancyhf{}%
  \renewcommand{\headrulewidth}{0.4pt}%
  \renewcommand{\footrulewidth}{0pt}%
  \fancyhead[L]{\footnotesize 43rd Kolloquium \"uber Kombinatorik (KolKom 2026)}%
  \fancyhead[R]{\footnotesize Berlin, 13--14 November 2026}%
}
\pagestyle{kolkom}

% Render the short abstract as an indented block with a bold "Abstract." label.
\RenewEnviron{abstract}{%
  \begin{quotation}\noindent\textbf{Abstract.}\enspace\BODY\end{quotation}%
}

% Author display tweaks
\renewcommand\Authsep{, }
\renewcommand\Authand{ and }
\renewcommand\Authands{, and }
\renewcommand\Affilfont{\itshape\small}
\setlength{\affilsep}{0.4em}

% Theorem environments (share one counter)
\theoremstyle{plain}
\newtheorem{theorem}{Theorem}
\newtheorem{lemma}[theorem]{Lemma}
\newtheorem{proposition}[theorem]{Proposition}
\newtheorem{corollary}[theorem]{Corollary}
\theoremstyle{definition}
\newtheorem{definition}[theorem]{Definition}
\newtheorem{conjecture}[theorem]{Conjecture}
\theoremstyle{remark}
\newtheorem*{remark}{Remark}

% =====================================================================
% TITLE
% =====================================================================
\title{Your talk title here}

% =====================================================================
% AUTHORS — one \author per person.
%   [1], [2] = affiliation indices (match the \affil blocks below).
%   The presenting author carries \thanks{...} with their contact email.
% =====================================================================
\author[1]{First Last\thanks{Presenting author. Contact: \texttt{you@example.org}}}
\author[2]{Coauthor One}
\author[1]{Coauthor Two}

% =====================================================================
% AFFILIATIONS — one \affil per institution. Numbered to match above.
% =====================================================================
\affil[1]{Your Institution (Acronym), Country}
\affil[2]{Other Institution (Acronym), Country}

\date{}

\begin{document}
\maketitle
\thispagestyle{kolkom}

% =====================================================================
% SHORT ABSTRACT — one paragraph, identical to the abstract you enter
% on the OpenReview submission form. Replace the placeholder below.
% =====================================================================
\begin{abstract}
  Replace this paragraph with your short abstract — the same text you
  enter in the "Abstract" field of the OpenReview form. State the main
  result or question at the level a non-specialist combinatorialist can
  follow.
\end{abstract}

% =====================================================================
% EXTENDED ABSTRACT — replace the content below. Aim for roughly two
% pages (a bit shorter or longer is fine). Structure with \section{...}
% (and optionally \subsection{...}) as needed.
% =====================================================================

\section{Introduction}

Replace this paragraph with the body of your abstract. You may use the
full range of \texttt{amsmath} / \texttt{mathtools} constructions,
theorem environments (\texttt{theorem}, \texttt{lemma},
\texttt{proposition}, \texttt{corollary}, \texttt{definition},
\texttt{conjecture}, \texttt{remark}), inline math like $\binom{n}{k}$,
and display math:
\[
  R(s,t) \;=\; \binom{s+t-2}{s-1} - O\!\left( \tfrac{1}{s} \right).
\]

Cite references with \cite{example-journal} or
\cite{example-preprint}. Add new entries to the bibliography below,
following the format in the REFERENCE FORMAT block at the top of this
file.

\begin{theorem}[Sample]
  For every integer $n \geq 1$ there is a graph on $n$ vertices with
  exactly $\binom{n}{2}$ edges.
\end{theorem}

% =====================================================================
% ACKNOWLEDGEMENTS — optional. Funders, advisors, and collaborators
% who are not coauthors of the underlying work belong here, not in the
% \author block above.
% =====================================================================
% \section*{Acknowledgements}
% This work was supported by ... The authors thank ... for helpful
% discussions.

% =====================================================================
% REFERENCES — replace these sample entries with your own.
% Follow the REFERENCE FORMAT block at the top of this file exactly.
% =====================================================================
\begin{thebibliography}{99}

\bibitem[AC26]{example-journal}
A.~Author and B.~Coauthor,
\emph{A sample journal article, replace with a real reference},
J. Sample Combin. \textbf{1} (2026), 1--10.
\href{https://doi.org/10.0000/sample}{doi:10.0000/sample}.

\bibitem[Aut25]{example-preprint}
C.~Author,
\emph{A sample preprint, replace with a real reference},
Preprint, 2025.
arXiv:\href{https://arxiv.org/abs/0000.00000}{0000.00000}.

\end{thebibliography}

\end{document}