prerex, version 5.4: 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 previewer, a prerex-enabled PDF viewer.

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 previewer is written in C++ using the Qt-4 toolkit and the poppler
library.

See the chart.pdf 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. See
src/prerex/README for installation instructions.

The effects of editing operations may be observed in any PDF viewer. The
"previewer" (prerex-viewer) application included in the prerex suite
is a PDF viewer that allows chart coordinates of course boxes, edges,
and background points to be tranferred back to the prerex command-line
through the "clipboard". See src/previewer/README for installation
instructions.

An alternative is to use a version of kpdf/okular (PDF viewers in KDE)
that has been patched to provide the same access to chart coordinates.
The "patches" sub-directory provides patches for several recent
versions of kpdf (KDE-3) and okular (KDE-4). See src/patches/README for
instructions.

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

prerex.sty, README.prerex, 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, previewer, and the kpdf/okular patches may
be modified and distributed according to the terms of the GNU General
Public Licence (version 2).