JeT
**My question**
How can I restart the section counter on Toc based on `\lecture` ?
**Context**
SamCarter taught me how to create a `tableofcontent` in Beamer, based on `\lecture`.
https://tex.stackexchange.com/questions/471060/lectures-toc-in-beamer
To restart the section counter after parts I use
`\makeatletter
\@addtoreset{section}{part}
\makeatother`
When I try this synthax
`\makeatletter
\@addtoreset{section}{lecture}
\makeatother`
no error but no apparent action on the section counters.
**Probably related,**
(I ask cause it might deserve a new question)how can I get the menu on top to be based on the split by `\lecture` ?
![LectureToc.png](/image?hash=bd5b90e7c8d6441a60d32c6f9248c896091ba061cd4eeca69fb1d651d0f60fe8)
MWE
```
\documentclass{beamer}
\usetheme{Copenhagen}
\makeatletter
\@addtoreset{section}{lecture}
\makeatother
\setbeamercolor{lecture in toc}{parent=structure}
\makeatletter
\long\def\beamer@lecture[#1]#2#3{%
\beamer@savemode
\mode<all>%
\refstepcounter{lecture}%
\def\beamer@currentlecturelabel{#3}%
\@onelevel@sanitize\beamer@currentlecturelabel
\def\beamer@lecturename{#2}%
\def\beamer@shortlecturename{#1}%
\ifx\beamer@onlylecture\@empty
\else
\expandafter\beamer@if@in@clist@TF\expandafter\beamer@onlylecture
\expandafter{\beamer@currentlecturelabel}%
{\beamer@inlecturetrue}%
{\beamer@inlecturefalse}%
\fi
\beamer@atbeginlecture
\beamer@resumemode
\addtocontents{toc}{%
\protect\usebeamercolor[fg]{lecture in toc}%
\vfill%
#2%
}
}
\makeatother
\title{Some Title}
\begin{document}
\begin{frame}
% \setcounter{secnumdepth}{-1}
% \tableofcontents[hideallsubsections]
\tableofcontents
\end{frame}
\lecture{Lecture1}{lec1}
\section{Section 1}
\subsection{Subsection 1a}
\frame{}
\subsection{Subsection 1b}
\frame{}
\subsection{Subsection 1c}
\frame{}
\section{Section 2}
\frame{}
\lecture{Lecture2}{lec2}
\section{Section 1}
\subsection{Subsection 1a}
\frame{}
\subsection{Subsection 1b}
\frame{}
\subsection{Subsection 1c}
\frame{}
\end{document}
```
Top Answer
samcarter
Similar to this [recent post on technique.fr](https://texnique.fr/osqa/questions/9233/reinitialisation-de-compteurs/9235) you can use `\AtBeginLecture{\beamer@tocsectionnumber=0}` to reset the toc section number at the start of a lecture.
```
\documentclass{beamer}
\usetheme{Copenhagen}
\setbeamercolor{lecture in toc}{parent=structure}
\makeatletter
\AtBeginLecture{%
\addtocontents{toc}{%
\protect\usebeamercolor[fg]{lecture in toc}%
\vfill%
\beamer@lecturename%
}
\beamer@tocsectionnumber=0
}
\makeatother
\title{Some Title}
\begin{document}
\begin{frame}
\tableofcontents
\end{frame}
\lecture{Lecture1}{lec1}
\section{Section 1}
\subsection{Subsection 1a}
\frame{}
\subsection{Subsection 1b}
\frame{}
\subsection{Subsection 1c}
\frame{}
\section{Section 2}
\frame{}
\lecture{Lecture2}{lec2}
\section{Section 1}
\subsection{Subsection 1a}
\frame{}
\subsection{Subsection 1b}
\frame{}
\subsection{Subsection 1c}
\frame{}
\end{document}
```
![Screen Shot 2020-09-22 at 23.53.55.png](/image?hash=fa76b393cbae7c5bc78b446e20065b25993774c99ff4b89b1b6c4157efbd9702)