Expr is a package for editing and displaying mathematical expressions within
text documents and for interfacing mathematical software, i.e. for symbolic
computing.

This software is a research prototype. No warranties can be assumed.

This is the final version of Expr. Its programming interfaces and its data
formats differ slightly from earlier versions.

The software is made available in source. Compiled versions are no longer
supported. Please compile the modules for your environment yourself. Some
example documents are also made available, serving for documentation
purposes.

To our best knowledge, the software works fine on all V4 implementations
supporting Oberon-2, with the following exceptions:
  a) With some MacOberon implementations printing may not work properly (using
the QuickDraw printing may hang the machine, using postscript printing may
clip incorrectly).
  b) Some versions of TextFrames still contain an error. This error leads to a
trap whenever a focused icon is decomposed with a middle mouse click. After
that trap the TextFrame usually cannot be used properly any more. Some
versions of TextFrames exhibit this problem only if the icon in question is
the last character in the text.

The software is stored in coded text files which can be expanded by the
AsciiCoder:
  EXPR.TXT contains all the modules needed for the standard package. Compile
them in the same order as they are encoded.
  MAPLE.TXT contains some additional material, allowing to interface the Maple
computer algebra system. To make use of this package, you need to have some
basic communication facilities in your Oberon environment (Module TCP) and to
have access to Maple on a Unix machine.
  GREEKS.TXT contains bitmap font files of the GreekSyntax font. This may be
used to display greek symbols. It is part of some Oberon implementations, but
not all of them.

Further, two document archives are provided. Get EXPRDOC.TXT in any case. It
contains general and fundamental user information:

  ExprUsage.Text       introductory user's guide (please read this first!)
  Expressions.Tool     lists most important commands and documents
  ExprPalette.Text     palette with some Extensions
  ExprDemo.Text        some example expressions

If you can use the link to Maple, get the MAPLEDOC.TXT archive also. It
contains the following documents:

  ExprMaple.Tool       commands used for maple interface
  ExprMaple.Text       introductory user's guide to maple interface
  MapleFormManip.Text  demonstration text for an interactive document
  ExprEvalIcons.Text   another demonstration text for an interactive document

A more detailed description of the entire project, the concepts, and the
implementation can be found in:

  Wolfgang Weck,
  On Document-Centered Mathematical Component Software
  PhD. Thesis, Diss ETH 11817.

Please send any questions or comments via e-mail to Weck@inf.ethz.ch .