How can I draw a horizontal line at the end of proofs? I use \begin{proof}....\end{proof}.
I use amsthm package without any modification.
[Tex/LaTex] How to draw a horizontal line at the end of proofs
amsthmrulestheorems
Related Solutions
One possibility would be to redefine the proof anvironment as defined in amsthm.sty (the definition uses \topsep6\p@\@plus6\p@\relax, so you could make some changes there). Another approach would be to use the front-end thmtools to define a new theorem-like structure behaving like the standard proof environment, but using the spaceabove key to control the vertical space above it. The following example illustrates this second approach and shows the different spacing for the new prf environment and the standard proof environment:
\documentclass{article}
\usepackage{amsthm}
\usepackage{thmtools}
\declaretheorem{theorem}
\declaretheoremstyle[%
spaceabove=-6pt,%
spacebelow=6pt,%
headfont=\normalfont\itshape,%
postheadspace=1em,%
qed=\qedsymbol%
]{mystyle}
\declaretheorem[name={Proof},style=mystyle,unnumbered,
]{prf}
\begin{document}
\begin{theorem}
A really important result.
\end{theorem}
\begin{prf}
And its proof with less space above.
\end{prf}
\begin{theorem}
A really important result.
\end{theorem}
\begin{proof}
And its proof with too much space above.
\end{proof}
\end{document}
if you're using amsthm, you don't need another proof environment. the features you want are already built in.
to get a heading "Proof of lemma", use
\begin{proof}[Proof of lemma]
to omit the box, just before \end{proof} insert
\renewcommand{\qedsymbol}{}
(this does not persist after the proof ends.)
both features are described in the manual: texdoc amsthm
Best Answer
You could patch
\endproof(the end macro of theproofenvironment) to insert a horizontal rule automatically. The following patch is provided viaetoolbox:The patch removes a vertical skip after ending
proof, and inserts\nobreaktogether with a horizontal rule (\hrulefill) so that they are not separated by a page break.