How can I strike through an expression (e.g. "2x") obliquely, e.g. from bottom left to top right, so as to indicate cancellation? With the \sout command from the ulem package, I can only strike horizontally.
Text-Decorations Strikeout Cancel – How to Strike Through Obliquely
cancelstrikeouttext-decorations
Related Solutions
Package ulem
Timebandit had written a solution with package ulem. The example was given as LaTeX, but the package also works with plain TeX:
\input ulem.sty
\sout{Hello World}
\bye
Package soul
Another LaTeX package soul can be used with plain TeX:
\input soul.sty
\st{Hello World}
\bye
I used soul to do the strikethrough, but had to define a displayst command to do strikethrough in display math mode. (soul commands only work with math as in \st{$abc$} . . . ) I also used the solution from Why is it that coloring in soul in beamer is not visible to make the color work. Use \setul{⟨underline depth⟩}{⟨underline thickness⟩} to change thickness of underline/strikethrough in soul.–
\documentclass[12pt]{beamer}
\usepackage{amsmath,amssymb,amsthm}
\usepackage{lmodern}
\usepackage[english]{babel}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{color,soul}
\makeatletter
\newcommand\SoulColor{%
\let\set@color\beamerorig@set@color
\let\reset@color\beamerorig@reset@color}
\makeatother
\setstcolor{red}
%\setul{}{1pt} Use this to change weight of underline/strikethrough
\newcommand{\displayst}[1]{\textrm{\SoulColor\st{$\displaystyle#1$}}}
\begin{document}
\begin{frame}
\begin{align*}
P = \{ & \displayst{S\rightarrow X_{1,4,2}}\\
& X_{1,4,1}\rightarrow X_{1,1,1}X_{2,3,1},\\
& X_{1,4,1}\rightarrow X_{1,1,1}X_{2,3,1}\}
\end{align*}
\end{frame}
\end{document}
Result:
Edit
I guess making this work nicely with soul required fixing a few things. The original solution I posted strikes behind the text, instead of on top of it, but this was solved in Strikeout in different color appears behind letters, not on top of them
\documentclass[12pt]{beamer}
\usepackage{amsmath,amssymb,amsthm}
\usepackage{lmodern}
\usepackage[english]{babel}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{xparse,xcolor,soul}
%% First define strikethrough command that strikes on top of letters, not behind them
\makeatletter
\NewDocumentCommand{\sttwo}{O{red}O{black}+m}
{%
\begingroup
\setulcolor{#1}%
\setul{-.5ex}{1pt}% <---- sets the undline/strikeout weight to 1pt
\def\SOUL@uleverysyllable{%
\rlap{%
\color{#2}\the\SOUL@syllable
\SOUL@setkern\SOUL@charkern}%
\SOUL@ulunderline{%
\phantom{\the\SOUL@syllable}}%
}%
\ul{#3}%
\endgroup
}
\makeatother
% Now make soul colors work with beamer
\makeatletter
\newcommand\SoulColor{%
\let\set@color\beamerorig@set@color
\let\reset@color\beamerorig@reset@color}
\makeatother
%Now make a version of strikethrough that works with display math
\newcommand{\displayst}[1]{\textrm{\SoulColor\sttwo{$\displaystyle#1$}}}
\begin{document}
\begin{frame}
\begin{align*}
P = \{ & \displayst{S\rightarrow X_{1,4,2}}\\
& X_{1,4,1}\rightarrow X_{1,1,1}X_{2,3,1},\\
& X_{1,4,1}\rightarrow X_{1,1,1}X_{2,3,1}\}
\end{align*}
\end{frame}
\end{document}
Result:
Best Answer
The
cancelpackage seems to do exactly what you want:If you're not satisfied with how the cancellation starts below the 1 and ends above the 0, have a look at Diagonal strikeout starting too low and ending too high.