Internet accessible mathematical service Files

OM-lite Maple plug-in. Andrew Solomon, May 2001
===================================================

General
=======
This plug-in is part of the JavaMath project (http://javamath.sourceforge.net)
and relies on OpenMath technology (http://www.openmath.org).

Functionality
=============
Enables the user to produce a 3-dimensional rendering of a Hasse Diagram 
in three easy steps:

1. Create a Hasse Diagram in Maple using the function 
CreateHasseDiagram which takes a list "l" and a function 
"le" (less-than-or-equals) which defines a partial order on "l".

2. Represent the Hasse Diagram as XML/OpenMath in a 
browser window using DrawHasse. At this point the user is given the opportunity
to change the name of the diagram from the default value of "user"
and to see the OpenMath representation of the diagram.

3. Display the diagram by pressing the button labelled "Take a Look"

System Requirements
===================
* Maple 6 or greater (probably works with earlier versions)
* A web browser
* An Internet connection

Installation and Configuration
===============================
* Extract om-lite.tar.gz 
* Modify the relevant settings at the top of om-lite.mpl

Issues
======
Characters "<" and ">" are stripped from vertex labels as they
confound the OpenMath parser on the server.

License
=======
This software is released under the terms of the GNU GPL. 

Acknowledgement
===============
The rendering component of this package is based on 
Ralph Freese's LatDraw applet http://www.math.hawaii.edu/~ralph/LatDraw/

Disclaimer
==========
This software is provided in the hope that it will be useful, 
but WITHOUT ANY WARRANTY; without even the implied warranty of 
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 

Examples
========

# If om-lite.mpl not in the current directory, use the full pathname
read("om-lite.mpl");

# a basic hasse diagram
h := [[0,[a,b]],[a,[1]],[b,[1]],[1,[]]];
DrawHasse(h);


## lattice of divisors of a natural number
N := 102;

le := proc(x,y) return y mod x = 0; end proc;

h := CreateHasseDiagram(select(i->N mod i = 0,[seq(j, j=1..N)]),le);
DrawHasse(h);