Hi everybody,
I'm sorry to disturb you with probably such an easy thing, but I just begin to use LaTeX and I would like to put a vertical line on the left of every mathematical proof I do (please see the attached example). How can I do in math mode?
Thank you,
Vince
Page Layout ⇒ Vertical Line left of Proofs
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Vertical Line left of Proofs
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Vertical Line left of Proofs
I think using the leftbar environment of the framed package will do what you wish, like so:
Code: Select all
Code, edit and compile here:
\documentclass{article}\usepackage{framed}\usepackage{amsmath,amsthm}\newenvironment{theorem}[1][Proof]{\begin{leftbar}\begin{proof}[#1]}{\end{proof}\end{leftbar}}\begin{document}Hello! This is text, leading to\begin{theorem}[Proof by Paradox]\begin{equation}\begin{split}\mathrm{A.}\quad & \mathrm{A} \oplus \mathrm{B} \\\mathrm{B.}\quad & 1 = 2\end{split}\end{equation}Case 1: Statement A is FALSE, meaning statement B is TRUE \\Case 2: Statement A is TRUE, meaning statement B is TRUE\end{theorem}And here's another one for you,\begin{theorem}\begin{gather}ax^2 + bx + c = 0 \\x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}\end{gather}\end{theorem}\end{document}
- localghost
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Vertical Line left of Proofs
You may also want to take a look at the mdframed package. The example of kaiserkarl13 modified accordingly.
For further customization please have a look at the comprehensive package manual.
Best regards and welcome to the board
Thorsten
Code: Select all
Code, edit and compile here:
\documentclass[11pt]{article}\usepackage[T1]{fontenc}\usepackage{mathtools}\usepackage{amsthm}\usepackage[framemethod=TikZ]{mdframed}\surroundwithmdframed[topline=false,rightline=false,bottomline=false,leftmargin=\parindent,skipabove=\medskipamount,skipbelow=\medskipamount]{proof}\begin{document}\noindentPreceding Text\begin{proof}[Proof by Paradox]\begin{equation}\begin{split}\mathrm{A.}\quad & \mathrm{A} \oplus \mathrm{B} \\\mathrm{B.}\quad & 1 = 2\end{split}\end{equation}Case 1: Statement A is FALSE, meaning statement B is TRUE \\Case 2: Statement A is TRUE, meaning statement B is TRUE\end{proof}Following Text\end{document}
Best regards and welcome to the board
Thorsten
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Avoidable Mistakes
¹ System: TeX Live 2025 (vanilla), TeXworks 0.6.10