prerex, version 2019-11-15. 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
or Qt-5 and poppler-qt libraries.

See chart.{pdf,svg} for a small example of a prerequisite
chart.

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 3.0 or higher 
  multido
  relsize
  calc
  hyperref

The use of pgf means that Postscript processing is not required.
Either pdflatex or latex -> dvips [ -> ps2pdf ] or latex -> dvipdfmx
or latex -> dvisvgm (with suitable driver options) will generate
charts.

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-6.8.0.tar.gz
  cd prerex-6.8.0
  ./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
that re-loads dynamically. 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.  There are two versions, for Qt-4 (vprerex-6.4.4)
and Qt-5 (vprerex-6.5.1), respectively.

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).
