CGT (Conceptual Graph Tools) is a partial implementation of Sowa's
Conceptual Structures Theory written in Quintus Prolog, although it
uses very few Quintus-specific features. It should be easily adaptable
to any Edinburgh-style Prolog.

The CGT package contains the following files:

Name		Size	Contents

qxp.pl		 5490	main file; consult and read this first
can_ops.pl	19102	canonical formation rules
type_ops.pl	13450	operations on the type hierarchy
gen_lin.pl	21282	linear form generator
rec_lin.pl	24245	linear form parser
gramaux.pl	10404	tokeniser
log_ops.pl	16270	propositional inference rules
misc.pl 	40313	DB management, referent expansions & contractions
list.pl		10509	list and set operations
canon.gr	 3906	a canonical basis (graphs)
canon.cty	 3330	a canonical basis (concept types)
canon.rty	 1527	a canonical basis (relation types)
canon.hrc	 1093	a canonical basis (type hierarchy)
canon.dsc	   26	a canonical basis (graph descriptions)
cgp_id.dat	   39	a canonical basis (database keys)
COPYING		17982	GNU General Public License
README			this file

According to the License you may not use (parts of) CGT for commercial
purposes. But if you want to do so, please drop me a note and I'm sure
we'll reach somee kind of agreement.

Each file begins with the following sections:

COPYRIGHT	copyright, warranty, and license notice
AUTHOR(S)	names and addresses of all authors that contributed
GENERALITIES	file identification (name, creation, description, etc.)
HISTORY		development of the changes: version, date, author, description
CONTENTS	predicates exported by the file (name & description)

The rest of the file contains the code for the predicates. Each one is
preceded by a comment section.

If you change the code please adhere to the following conventions:
	- add your name and address to the AUTHOR(S) section
	- add an abbreviation for your name in the GENERALITIES section
	- update the HISTORY section using your abbreviation
	- if you change existing predicates put a comment with your
	  abbreviation next to the change
	- if you add new predicates also add "comment sections" in the
	  same style

I would also very much appreciate if you could send your changes back
to me, so I may keep a master version to send regularly to everyone
interested in CGT.

Anything you write (working papers, reports, articles, etc.) about
your work using GET is also of great interest to me (and probably
everyone else working with CGT).

Bug reports, criticisms, but not flames (I know that parts of the code
are ghastly), and suggestions are most welcome.

Michel Wermelinger
Dept. de Informatica, Univ. Nova de Lisboa, Quinta da Torre
P - 2825 Monte da Caparica, PORTUGAL
Phone: (+351) (1) 295 44 64 ext. 1360  Internet: mw@fct.unl.pt
