CMU Artificial Intelligence Repository
TimeGraph II (TG-II): Reasoning about Qualitative Temporal
TimeGraph II (TG-II) handles the set of the relations of the Point
Algebra and of the Pointizable Interval Algebra (also called Simple
Interval Algebra by P. van Beek). Temporal relations are represented
through a "timegraph", a graph partitioned into a collection of "time
chains" which are automatically structured for efficiency. The system
is scalable, in the sense that the storage tends to remain linear in
the number of relations asserted. Efficient query handling is achieved
through a time point numbering scheme and a "metagraph" data
as the files tg-ii.readme and tg-ii-1.tar.gz
Version: 1.0 (30-MAR-94)
Requires: Common Lisp
Ports: Tested under Allegro CL 4.2 and Lucid CL 4.0.0.
Copying: Copyright (C) 1994 by Istituto per la Ricerca Scientifica e
Tecnologica (IRST) (38050 Povo, Trento Italy) and the
Trustees of the University of Rochester (Rochester, NY
14627, USA). All rights reserved.
GNU GPL v2.
Use, copying, and distribution permitted, provided you
report *ALL* bugs, bug fixes, and ports to
and let the authors know that you've retrieved a copy of
TimeGraph II by anonymous ftp, by sending them a message
to the same address. (See README and COPYRIGHT.TEXT for
CD-ROM: Prime Time Freeware for AI, Issue 1-1
Bug Reports: firstname.lastname@example.org
Mailing List: To be put on the email@example.com mailing list,
send your request to firstname.lastname@example.org.
Author(s): Alfonso Gerevini
Algebra, Authors!Gerevini, Authors!Schubert,
Interval Algebra, Knowledge Representation, Lisp!Code,
Point Algebra, Pointizable Interval,
Reasoning!Temporal Reasoning, Simple Interval Algebra, TG-II,
Temporal Reasoning, Temporal Relations, TimeGraph-II
For a description of the theory underlying the system see
 Alfonso Gerevini and Lenhart Schubert, "Efficient Temporal
Reasoning through Timegraphs", in Proceedings of IJCAI-93.
 Alfonso Gerevini and Lenhart Schubert, "Temporal Reasoning in
TimeGraph I-II", SIGART Bulletin 4(3), July 1993.
 Alfonso Gerevini and Lenhart Schubert, "Efficient Algorithms
for Qualitative Reasoning about Time", Artificial Intelligece,
to appear. Also available as IRST Technical Report 9307-44,
IRST 38050 Povo, TN Italy; or Tech. report 496, Computer Science
Department, University of Rochester, Rochester 14627 NY, USA.
Last Web update on Mon Feb 13 10:27:56 1995