Dealing with rotated curly brace problem in lists?

Question

So I am making a presentation in beamer for a class and I decided on using curly braces around multiple items in an itemize environment that are uncovered one by one. So, following the advice I got from another question here, I got the curly braces to show up around chosen items when I want them too, except some braces are inexplicably rotated. Here is what I mean,
Here is my best attempt at a MWE:

\documentclass{beamer}
\usepackage[utf8]{inputenc}
\usetheme{metropolis}
\usepackage[normalem]{ulem}
\usepackage{amsmath,lmodern,calc,tikz,textcomp}
\usetikzlibrary{tikzmark,calc, decorations.pathreplacing}

\begin{document}


\begin{frame}

\begin{itemize}
\setlength\itemsep{0.7em}
\item\only<1>{\(b > v > p\)}\onslide<2->{\sout{\(b > v > p\)}}\tikzmark{start}
\item\only<2>{\(p > b > v\)}\only<3->{\sout{\(p > b > v\)}}\tikzmark{end}
\item\only<3>{\(b > p > v\)}\only<4->{\sout{\(b > p > v\)}}\tikzmark{start1} \tikzmark{end1}
\item\only<4>{\(v > b > p\)}\only<5->{\sout{\(v > b > p\)}}\tikzmark{start2}
\item\only<5>{\(p > v > b\)}\only<6->{\sout{\(p > v > b\)}}\tikzmark{end2}
\item\only<6>{\(v > p > b\)}\only<7->{\sout{\(v > p > b\)}}\tikzmark{start3} \tikzmark{end3}

\only<3->{\begin{tikzpicture}[remember picture,overlay]
\draw[decorate,decoration={brace,raise=12pt}]
  ([yshift=2ex]{{pic cs:end}|-{pic cs:start}}) --
    node[xshift=15pt,anchor=west] {No change by raising} 
  ([yshift=-0.5ex]pic cs:end);
\end{tikzpicture}}

\only<4->{\begin{tikzpicture}[remember picture,overlay]
\draw[decorate,decoration={brace,raise=12pt}]
  ([yshift=2ex]{{pic cs:end}|-{pic cs:start1}}) --
    node[xshift=15pt,anchor=west] {Raising won, but now neg. profit} 
  ([yshift=-0.5ex]pic cs:end1);
\end{tikzpicture}}

\only<6->{\begin{tikzpicture}[remember picture,overlay]
\draw[decorate,decoration={brace,raise=12pt}]
  ([yshift=2ex]{{pic cs:end}|-{pic cs:start2}}) --
    node[xshift=15pt,anchor=west] {No change by lowering} 
  ([yshift=-0.5ex]pic cs:end2);
\end{tikzpicture}}

\only<7->{\begin{tikzpicture}[remember picture,overlay]
\draw[decorate,decoration={brace,raise=12pt}]
  ([yshift=2ex]{{pic cs:end}|-{pic cs:start3}}) --
    node[xshift=15pt,anchor=west] {Lost by lowering} 
  ([yshift=-0.5ex]pic cs:end3);
\end{tikzpicture}}

\end{itemize}

\end{frame}


\end{document}

No matter what I do, or how much I increase the space between the items, the rotation on some braces remain. Can someone please help me with this error?

Answer 1

The minimal fix:

• Remove the space between the \tikzmarks: replace \tikzmark{start1} \tikzmark{end1} by \tikzmark{start1}\tikzmark{end1}, and likewise for the other space between tikzmark{start3} and tikzmark{end3}.

• In the code for the second brace, replace {pic cs:end}|-{pic cs:start1} by {pic cs:end1}|-{pic cs:start1} (adding 1 to end). Do the same for the third and fourth brace: replace end by end2 and end3, respectively.

To clean up the code a bit, I suggest to define the command

\mybrace{<start mark>}{<end mark>}{<alignment mark>}{<text>}

as

\newcommand\mybrace[4]%
   {\begin{tikzpicture}[remember picture,overlay]
    \draw[decorate,decoration={brace,raise=12pt}]
      ([yshift=2ex]{{pic cs:#3}|-{pic cs:#1}}) --
      node[xshift=15pt,anchor=west] {#4} 
      ([yshift=-0.5ex]{{pic cs:#3}|-{pic cs:#2}});
    \end{tikzpicture}%
   }

Then the code for the braces reduces to

\only<3->{\mybrace{start}{end}{end}{No change by raising}}
\only<4->{\mybrace{start1}{end1}{end}{Raising won, but now neg. profit}}
\only<6->{\mybrace{start2}{end2}{end}{No change by lowering}}
\only<7->{\mybrace{start3}{end3}{end}{Lost by lowering}}

The extra alignment mark helps to align the braces below each other if the itemized texts are of different lengths. If there is nothing to align with (like for the first brace), take the end mark as alignment mark.

Here is the complete code and the result.

\documentclass{beamer}
\usepackage[utf8]{inputenc}
\usetheme{metropolis}
\usepackage[normalem]{ulem}
\usepackage{amsmath,lmodern,calc,tikz,textcomp}
\usetikzlibrary{tikzmark,calc, decorations.pathreplacing}
\newcommand\mybrace[4]%
   {\begin{tikzpicture}[remember picture,overlay]
    \draw[decorate,decoration={brace,raise=12pt}]
      ([yshift=2ex]{{pic cs:#3}|-{pic cs:#1}}) --
      node[xshift=15pt,anchor=west] {#4} 
      ([yshift=-0.5ex]{{pic cs:#3}|-{pic cs:#2}});
    \end{tikzpicture}%
   }
\begin{document}
\begin{frame}

\begin{itemize}
\setlength\itemsep{0.7em}
\item\only<1>{\(b > v > p\)}\onslide<2->{\sout{\(b > v > p\)}}\tikzmark{start}
\item\only<2>{\(p > b > v\)}\only<3->{\sout{\(p > b > v\)}}\tikzmark{end}
\item\only<3>{\(b > p > v\)}\only<4->{\sout{\(b > p > v\)}}\tikzmark{start1} \tikzmark{end1}
\item\only<4>{\(v > b > p\)}\only<5->{\sout{\(v > b > p\)}}\tikzmark{start2}
\item\only<5>{\(p > v > b\)}\only<6->{\sout{\(p > v > b\)}}\tikzmark{end2}
\item\only<6>{\(v > p > b\)}\only<7->{\sout{\(v > p > b\)}}\tikzmark{start3} \tikzmark{end3}
\only<3->{\mybrace{start}{end}{end}{No change by raising}}
\only<4->{\mybrace{start1}{end1}{end}{Raising won, but now neg. profit}}
\only<6->{\mybrace{start2}{end2}{end}{No change by lowering}}
\only<7->{\mybrace{start3}{end3}{end}{Lost by lowering}}
\end{itemize}

\end{frame}
\end{document}