#############################################################################
# 
# FILE readme.txt of the Canon Tensor Package 
# version 2.0 - differential invariants
# InvarDatabase works on top of Canon package
#
# Installation Instructions
#
# Language: Maple 9.5,10,11. (There is a version for Mathematica)
#
# Description: The Canon tensor package is a fast manipulator of generic
#    scalar polynomial expressions formed from the Riemann tensor of a
#    four-dimensional metric-compatible connection and its covariant
#    derivative. The package can maximally simplify any polynomial 
#    containing tensor products of up to seven Riemann tensors within 
#    seconds. 
#    It has been implemented both in Mathematica and Maple algebraic systems. 
#    This is the Maple implementation.
#
# Developers: Renato Portugal (database, Maple version)
#             Laboratorio Nacional de Computacao Cientifica (LNCC), Brazil
#             and
#             Jose M. Martin-Garcia, David Yllanes 
#             (database, Mathematica version)
#             Instituto de Estructura de la Materia (IEM), CSIC, Madrid.
#
# Contact and bug report: Portugal at Lncc.Br
#
############################################################################

The authors kindly ask that researchers who have used the package cite 
references describing it. 

INSTALLATION INSTRUCTIONS

Installation instructions:

1. Download the file Invar.zip into your machine. It contains the 
   following files:
     compiled code (Canon.mla)
     compiled database (InvarDatabase.mla)
     help on line (Canon.hdb)
     external help file (help.mws)
     test file (test.mpl)
     this file (readme.txt)

1a. It may contain, but need not 
       preprints describing the Canon tensor package (Canon.pdf,...)
       source code (Canon.mpl)
       database source code (Invar1.mpl,Invar2.mpl,Invar3.mpl,Invar4.mpl,
		Invar5.mpl,Invar6.mpl,Invar1dual.mpl,Invar2dual.mpl,
		Invar3dual.mpl,Invar4dual.mpl,Invar5dual.mpl)
   
2. Unzip the file Invar.zip (with unzip or pkzip).

3. Save the code and the help files in a directory. Let's say  C:\Invar.

4. Start a Maple session. Issue the command:
                  libname := "C:/Invar", libname;  
                                          or
                  libname := "C:\\Invar", libname; 

   The next command is:
                  with(Invar);    [or with(Canon);]

   The output is something like:
                  [AbsorbMetric, Canonical, InvToPerm, InvToRiemann,...]

NOTE: In Windows one can use the forward slash ("/") or a double back 
slashes ("\\") in directory names.

You can use the package now. For help try ?Invar. 
If anything goes wrong, give the command restart before trying again. 

Example:

> libname:= "C:/Invar", libname:

> with(Invar);   # or with(Canon);

        [AbsorbMetric, CD, Canonical, CyclicSimp, Define, InvToPerm, 
         InvToRiemann, MaxDualIndex, MaxIndex, PermToInv, PermToRiemann, 
         Print, RicciToRiemann, RiemannSimp, RiemannToInv, RiemannToPerm,
         RiemannToRicci, RiemannToWeyl, UnPrint, WeylToRiemann]


Try the help command:
> ?Invar     

or

> Print(T[a,-b]);

                         a 
                       T  
                           b

test:

> read "C:/Invar/test.mpl";

This command performs 56 tests which, if everything is
working, should all return an "ok".

Hint: One can avoid to setup every time the variable libname by putting 
this information in the maple initialization file (see ?maple and ?libname).
For unix users: the initialization file is called .mapleinit and stays in 
the home directory. One should edit it and add the line: 
libname := "C:/Invar", libname:  

Acknowledgment:
We thank Dr. Carol Phillips (CPC Program Library) for suggestions.