I want to build a file with a number of math problems and solutions, like:
Problems
...
...
...
Solutions
...
...
...
I want to link back and forth between problems and the corresponding solutions, and vice-versa. In particular, it would be nice to be able to click on the problem number (1., 2., ...) and have it jump to the corresponding solution, and vice-versa.
Is there a way to do this without having to repeatedly type label-ref for every problem and solution?
Here, I define \addProblemPlusSolution{}{} for defining problem/solution sets, and then \showProblemsThenSolutions to output all the problems sequentially, followed by all of the solutions, with hyperlinked references back and forth. No \labels and \refs are placed explicitly by the user, but are auto-generated by \showProblemsThenSolutions.
I don't do anything special in the formatting, other than to create a new \subsection* for each problem and solution, respectively. However, one could add a page break between problems and solutions, additional sectioning, etc.
I use Werner's label solution (the \mynameis macro) at How to force a label to be a given string?
\documentclass{article}
\usepackage{hyperref}
\usepackage{lipsum}
\usepackage{ifthen}
\makeatletter
\newcommand{\mynameis}[1]{%
\phantomsection#1% Mark hyperlink
\renewcommand{\@currentlabel}{#1}%
\renewcommand{\@currentlabelname}{#1}}
\makeatother
\newcounter{probcount}
\newcounter{pcindex}
\newcommand\addProblemPlusSolution[2]{%
\stepcounter{probcount}
\expandafter\def\csname P\romannumeral\theprobcount\endcsname{#1}%
\expandafter\def\csname S\romannumeral\theprobcount\endcsname{#2}%
}
\newcommand\showProblemsThenSolutions{%
\setcounter{pcindex}{0}%
\whiledo{\thepcindex < \theprobcount}{%
\stepcounter{pcindex}%
\subsection*{\mynameis{Problem \thepcindex}%
\label{LP\romannumeral\thepcindex}
{\small\mdseries(see \ref{LS\romannumeral\thepcindex})}}
\csname P\romannumeral\thepcindex\endcsname
}%
\setcounter{pcindex}{0}%
\whiledo{\thepcindex < \theprobcount}{%
\stepcounter{pcindex}%
\subsection*{\mynameis{Solution \thepcindex}%
\label{LS\romannumeral\thepcindex}
{\small\mdseries(see \ref{LP\romannumeral\thepcindex})}}
\csname S\romannumeral\thepcindex\endcsname
}%
}
\begin{document}
\addProblemPlusSolution
{
\lipsum[1-3]
\[ y = mx + b\]
}{
\[ m = 3, \quad b = 12 \]
\lipsum[3-4]
}
\addProblemPlusSolution
{
\lipsum[2-3]
\[E = mc^2\]
}{
\[ c = 186,000 \textrm{mi/s} \]
\lipsum[4]
}
\showProblemsThenSolutions
\end{document}
