prerex, version 6.5.3: Macros for prerequisite charts, with associated
editor and viewer applications. 

This package consists of 

  prerex.sty 
    a LaTeX package for producing charts of course nodes
    linked by arrows representing pre- and co-requisites,

  prerex 
    an interactive program for creating and editing chart
    descriptions, and

  vprerex ("visual prerex") a GUI and previewer for prerex.

The implementation of prerex.sty is built on pgf, so that it may be
used equally happily with latex or pdflatex; prerex is written in C and
vprerex is written in C++ using the Qt-4 and poppler libraries.

See chart.{pdf,html} for a small example of a prerequisite chart and
real-life examples at

http://www.cs.queensu.ca/students/undergraduate/prerequisites/

Prerequisite charts are useful to students selecting courses and
planning their programs, and to faculty and staff advising students
and managing curriculum development. Conventional sources of course,
program and timetable information are rarely in a user-friendly format.
Faculty and staff advisors, being already fairly familiar with their
courses and programs, often do not appreciate how inconvenient it is
for students to access all the information they need to make course
choices. 

The crucial tool in the prerex suite is "prerex.sty", a macro package
that defines a "chart" environment and commands to specify construction
of course boxes and directed arrows between them.

prerex.sty depends on

  pgf (and add-on tikz), version 1.18 or higher 
  multido
  relsize
  calc
  ifthen
  zref-savepos
  hyperref

The use of pgf means that Postscript processing is not required;
either pdflatex or latex -> dvips [ -> ps2pdf ] may be used.

Installation of prerex.sty:

  + copy prerex.sty to your-texmf-tree/tex/latex/misc
  + copy doc/prerex.{tex,pdf} to your-texmf-tree/doc/latex/misc
  + if necessary, refresh the TeX database (e.g., texhash)
  + copy doc/prerex.sty.7 to sub-directory man7 of a man directory on your 
    MANPATH
  + test by doing 

       man 7 prerex.sty
       pdflatex chart.tex

See doc/prerex.pdf for detailed documentation.

The prerex editor allows interactive editing of the chart environments
of LaTeX source files. It supports add, remove, cut-and-paste, and edit
operations on course boxes and arrows, and vertical or horizontal shifts
of the whole diagram or selected sets of course boxes. When a course box
is moved, the arrows into and out of it automatically follow. To install
on most Unix-like platforms, including OS-X and Cygwin on Windows:

  tar zxvf prerex-6.5.2.tar.gz
  cd prerex-6.5.2
  ./configure  [--prefix=$HOME]
  make
  make install  (as root if necessary)

The prerex editor will also build on the MinGW platform on Windows if
the readline package in the gnuwin32.sourceforge.net repository has been
installed.

The effects of editing operations may be observed in any PDF viewer.
The vprerex (visual prerex) application included in the prerex suite
is a GUI and viewer for the prerex editor. It may be used just as a
minimalist viewer of arbitrary PDF files but supports editing of
charts generated using prerex.sty by allowing coordinates of course
boxes, arrows, and background points to be conveyed back to the prerex
editor command-line using the clipboard. See the INSTALL in the tarball
for installation instructions.

See the file doc/intro.pdf for an overview of the prerex system.

prerex.sty, README, prerex.1, prerex.5, prerex.sty.7, prerex.tex and
chart.tex may be modified and distributed according to the terms of the
LaTeX Project Public License.

The source files for prerex and vprerex may be modified and distributed
according to the terms of the GNU General Public Licence (version 2).
