Blocks at the End of a Solution Structure

Question

so a couple of months ago I created my own package. Everything in it works great, and so far it does everything I need it to do, the way I need it to. But I want to change one thing. When I made the package, I found it necessary to create a structure declaration in the package that says

\newtheorem*{solution}{Solution}

Until now, I have been very happy with it. But I've decided (in order to separate the solutions from the surrounding text) that I want the structure to add a black square at the end every time the structure ends. Could somebody tell me how to modify my code to do this?

That's fine for the proof environment, but how do I force my created environment to do a similar practice? — Higgie2718, Feb 04 '14 at 02:46

Gonzalo Medina · Accepted Answer · 2014-02-04T02:52:03.390

3

Instead of \newtheorem*{solution}{Solution}, add the following lines:

\RequirePackage{thmtools}

\declaretheoremstyle[
  qed=$\blacksquare$,
  numbered=no,
  bodyfont=\itshape
]{mystyle}
\declaretheorem[style=mystyle]{solution}

Since \blacksquare requires amssymb, you will also need this package (if you are not already loading it):

\RequirePackage{amssymb}

An example with a document:

\documentclass{article}
\usepackage{amssymb}
\usepackage{amsthm}
\usepackage{thmtools}
\usepackage{lipsum}

\declaretheoremstyle[
  qed=$\blacksquare$,
  numbered=no,
  bodyfont=\itshape
]{mystyle}
\declaretheorem[style=mystyle]{solution}

\begin{document}

\begin{solution}
\lipsum*[4]
\end{solution}

\end{document}

enter image description here

edited Feb 04 '14 at 02:52

answered Feb 04 '14 at 02:46

Gonzalo Medina

505,128

What does the {mystyle} part do? – Higgie2718 Feb 04 '14 at 02:49
mystyle is the name of the defined style. You can use any other name you like more. – Gonzalo Medina Feb 04 '14 at 02:50

score 1 · Answer 2 · answered Feb 04 '14 at 02:49

You could make solution be similar to proof of amsthm by using the following construction:

enter image description here

\documentclass{article}
\usepackage{amsthm,amsmath,amssymb}% http://ctan.org/pkg/{amsthm,amsmath,amssymb}

\renewcommand{\qedsymbol}{$\blacksquare$}
\makeatletter
\newcommand{\solutionname}{\textbf{Solution}}
\newenvironment{solution}[1][\solutionname]{\par
  \pushQED{\qed}%
  \normalfont \topsep6\p@\@plus6\p@\relax
  \trivlist
  \item[\hskip\labelsep
    #1\@addpunct{.}]\ignorespaces
}{%
  \popQED\endtrivlist\@endpefalse
}
\makeatother

\begin{document}
\begin{solution}
  \begin{equation*}
    G(t)=L\gamma!\,t^{-\gamma}+t^{-\delta}\eta(t) \qedhere
  \end{equation*}
\end{solution}
\end{document}

The above definition for solution is taken directly from amsclass.dtx where proof is defined. The only thing I've changed is the title.

Blocks at the End of a Solution Structure

2 Answers2