Temporal Reasoning:

   See also KNOWBEL above.

   MATS     -- Metric/Allen Time System
               Contact: Henry Kautz <kautz@research.att.com>
               MATS is a Common Lisp program which solves temporal
               constraint problems.  Input constraints are either
               difference inequalities or Allen-style qualitative constraints.

   TMM      -- New implementation of Dean & McDermott's Temporal Map
               Manager system written in Common Lisp.  
               See SIGART Bulletin 4(3), July 1993.
               Contact: carciofi@src.honeywell.com

   MTMM     -- Modified version of Dean & McDermott's TMM written in
               MCL.  Available on diskette.
               Contact: Eckehard Gross <gross@gmd.de>

   TimeGraph-- Metric and Qualitative temporal reasoning system which
               handles (<, =, >) point relations, bounds on absolute
               calendar/clock times, and bounds on durations. Data entry
               and retrieval is through interval or point relations.
               The system is scalable in the sense that storage
               remains linear in the number of relations added.
               Efficient retrieval is achieved through a simple 
               timepoint numbering scheme and metagraph structure.
               See SIGART Bulletin 4 (3), pp. 21-25, July 1993.
               Contact: Lenhart Schubert (schubert@cs.rochester.edu)

   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
   structure. TG-II is written in Common Lisp.  For a description of the
   theory underlying the system see:

      [1] Alfonso Gerevini and Lenhart Schubert, "Efficient Temporal
	  Reasoning through Timegraphs", in Proceedings of IJCAI-93.
      [2] Alfonso Gerevini and Lenhart Schubert, "Temporal Reasoning in 
	  TimeGraph I-II", SIGART Bulletin 4(3), July 1993.
      [3] 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.

   TimeGraph II is available by anonymous ftp from

      ftp.cs.rochester.edu:/pub/packages/knowledge-tools/

   as the files tg-ii.readme and tg-ii-1.tar.gz. If you retrieve a copy
   of TimeGraph II by anonymous ftp, please let them know that you've
   retrieved a copy by sending a message to 

      bug-tg2-request@cs.rochester.edu

   For more information, contact Alfonso Gerevini <gerevini@irst.it> or
   Lenhart Schubert <schubert@cs.rochester.edu>.

   Tachyon  -- Performs constraint satisfaction for point-based metric
               reasoning.  Qualitative constraints are also handled by
               translation into quantitative ones.  Written in C++. 
               See SIGART Bulletin 4(3), July 1993.
               Contact: Richard Arthur (arthurr@crd.ge.com)
               
   TimeLogic-- The TimeLogic system is an interval-based forward
               chaining inference engine and database manager of
               temporal constraints.  Relational constraints,
               indicating relative order between intervals, are based
               on Allen's interval logic.  The TimeLogic system also
               supports durational constraints, indicating relative
               magnitude between intervals, and reference links, used
               for the explicit or automatic construction of interval
               hierarchies.  Constraints are posed and propagated in
               user-defined contexts with inheritance. Supports relative
               metric constraints but no absolute dates or times.
               Written in Common Lisp.
               Contact: Peggy Meeker (timelogic-request@cs.rochester.edu)

   TemPro   -- A temporal constraint system that uses both interval
               algebra and point-based algebra. Written in Common Lisp.
               Contact: J-P Haton <jph@loria.fr> or
                        F. Charpillet <charp@loria.fr>

   TIE      -- Temporal Inference Engine.  Written in Common Lisp.
               Contact: E. Tsang (Essex University, UK)

   TCNM (Temporal Constraint Network Manager) manages non-disjunctive
   metric constraints on time-points and on durations in an integrated
   way. These constraints allow us express absolute, qualitative and
   metric constraints on time-points and on durations, which are managed
   in an integrated way. In the updating processes, a non-redundant and
   global consistent Temporal Constraint Network is always maintained by
   means of an efficient and complete propagation method, with a O(n**2)
   temporal complexity. Sound and complete retrieval processes have a
   constant cost. Written in Common Lisp.  For more information, contact
   Federico A. Barber <fbarber@dsic.upv.es>.  See also SIGART Bulletin
   4(3), July 1993.

Theorem Proving/Automated Reasoning:

   Coq is the Calculus of Inductive Constructions. It runs in 
   Caml-Light and is available by anonymous ftp from

      ftp://ftp.inria.fr/INRIA/coq/ (unix version)
      ftp://ftp.inria.fr/INRIA/coq/ (mac version)

   The Mac version is standalone, not requiring Caml-Light. The unix
   version requires Caml-Light, however, which is available from

      ftp://ftp.inria.fr/lang/

   Documentation is included in the distribution. Questions and comments
   should be directed to the Coq hotline <coq@pauillac.inria.fr>. 

   DTP is a general first-order theorem prover incorporating
   intelligent backtracking and subgoal caching, as well as a trace
   facility that can display proof spaces graphically.  It is
   implemented in (CLtL2) Common Lisp, and is available on the web at
     http://don.geddis.org/dtp/

   Contact Don Geddis <Geddis@CS.Stanford.EDU> for more information.

   Elf implements the LF Logical Framework (based on the theory of
   dependent types) and gives it a logic programming interpretation in
   order to support search and the implementation of other algorithms (e.g.
   evaluation or compilation in programming languages).  It comes with a
   number of examples from logic and the theory of programming languages
   such as the Church Rosser theorem for the untyped lambda-calculus and
   type soundness for Mini-ML.  It is written in Standard ML and includes
   some support code for editing and interaction in gnu-emacs. It is
   available by anonymous ftp from 

      ftp://ftp.cs.cmu.edu/afs/cs/user/fp/public/

   as the files README (general information), elf-04.tar.Z (Version 0.4
   of Elf, 1 Jul 1993), elf-examples.tar.Z (Version 0.4 of Elf examples,
   unchanged from Version 0.3), and elf-papers/ (DVI files for papers
   related to LF and Elf, including a "tutorial" and a bibliography). For
   more information, contact Frank Pfenning <fp+@cs.cmu.edu>,
   Department of Computer Science, Carnegie Mellon University.

   FRAPPS (Framework for Resolution-based Automated Proof Procedures) is
   a portable resolution theorem-prover written in Common Lisp. It is
   available via anonymous ftp from a.cs.uiuc.edu:/pub/frapps [128.174.252.1].
   If you take a copy of FRAPPS, please send a short note to Prof.
   Alan M. Frisch <frisch@cs.uiuc.edu>.

   Gazer is a sequent calculus based system for first order logic with a
   novel inference rule, gazing, that enables the system to determine
   which of a possibly large number of definitions and lemmas should be
   used at any point in a proof. Available from the authors, Dave
   Barker-Plummer <plummer@cs.swarthmore.edu> and Alex Rothenberg
   <alex@cs.swarthmore.edu>. 

   ISABELLE-93. Isabelle is a highly automated generic theorem prover
   written in Standard ML.  New logics are introduced by specifying their
   syntax and rules of inference.  Proof procedures can be expressed
   using tactics and tacticals. Isabelle comes with 8 different logics,
   including LCF, some modal logics, first-order logic, Zermelo-Fraenkel
   set theory, and higher-order logic. Isabelle-93 is not upwardly
   compatible with its predecessor, but comes with advice on converting
   to the new simplifier.  Isabelle-93 is available by anonymous ftp from
   the University of Cambridge,

      ftp.cl.cam.ac.uk:/ml/ [128.232.0.56]

   as Isabelle93.tar.gz. It is also available from the Technical
   University of Munich, 

      ftp://ftp.informatik.tu-muenchen.de/lehrstuhl/nipkow/ [131.159.0.198]

   The distribution includes extensive documentation, including a 71-page
   introduction, an 85-page reference manual, and a 166-page description of
   the various logics supplied with Isabelle. For more information, write
   to Larry.Paulson@cl.cam.ac.uk and Tobias.Nipkow@informatik.tu-muenchen.de.
   An Emacs-Lisp package for Isabelle by David.Aspinall@dcs.ed.ac.uk
   is available from  

      ftp.dcs.ed.ac.uk:/pub/da/isa-mode.tar.gz

   The users mailing list is isabelle-users@cl.cam.ac.uk and is moderated.

   KEIM is a collection of software modules, written in Common Lisp with
   CLOS, designed to be used in the production of theorem proving
   systems.  KEIM is intended to be used by those who want to build or
   use deduction systems (such as resolution theorem provers) without
   having to write the entire framework. KEIM is also suitable for
   embedding a reasoning component into another Common Lisp program.
   KEIM offers a range of datatypes implementing a logical language of
   type theory (higher order logic), in which first order logic can be
   embedded.  KEIM's datatypes and algorithms include: types; terms
   (symbols, applications, abstractions), environments (e.g., associating
   symbols with types); unification and substitutions; proofs, including
   resolution and natural deduction style. KEIM also provides
   functionality for the pretty-printing, error handling, formula parsing
   and user interface facilities which form a large part of any theorem
   prover. Implementing with KEIM thus allows the programmer to avoid a
   great deal of drudgery.  KEIM has been tested in Allegro CL 4.1 and
   Lucid CL 4.0 on Sun 4 workstations.  KEIM is available for
   noncommercial use via anonymous FTP from

      js-sfbsun.cs.uni-sb.de:/pub/keim/keim*

   For more information contact Dan Nesmith, Fachbereich Informatik/AG
   Siekmann, Universitaet des Saarlandes, Postfach 1150, D-66041
   Saarbruecken, Germany, or send email to keim@cs.uni-sb.de.  A mailing
   list for KEIM users is also being set up.  Send mail to
   keim-users-request@cs.uni-sb.de to be put on the list.

   MVL      -- ftp://t.uoregon.edu/mvl/ [128.223.56.46]
               Contact: ginsberg@t.stanford.edu
               Multi-valued logics

   Boyer-Moore -- ftp.cli.com:/pub/nqthm/nqthm.tar.Z
                  rascal.ics.utexas.edu:/pub/nqthm   128.83.138.20
   See also the pub/proof-checker/ subdirectory, which contains Matt
   Kaufmann's proof checking enhancements to nqthm. 

   Nqthm-1992 is the Boyer-Moore theorem prover. The 1992 version of the
   theorem prover is upwardly compatible with the previous (1987)
   version. Included in the distribution are thousands of Nqthm-checked
   theorems formulated by Bevier, Boyer, Brock, Bronstein, Cowles,
   Flatau, Hunt, Kaufmann, Kunen, Moore, Nagayama, Russinoff, Shankar,
   Talcott, Wilding, Yu, and others. The release of Nqthm-1992 includes
   three revised chapters of the book `A Computational Logic Handbook',
   including Chapter 4, on the formal logic for which the system is a
   prover, and Chapter 12, the reference guide to user commands.  Nqthm
   runs in Common Lisp, and has been tested in AKCL, CMU CL, Allegro CL,
   Lucid CL, MCL, and Symbolics CL. Nqthm-1992 is available by anonymous
   ftp from

      ftp.cli.com:/pub/nqthm/nqthm-1992/  [192.31.85.129]

   as the file nqthm-1992.tar.Z. See the file README in the same
   directory for instructions on retrieving nqthm.  See also the 

      /pub/pc-nqthm/pc-nqthm-1992/

   directory (files README-pc and pc-nqthm-1992.tar.Z), which contains
   Matt Kaufmann's interactive proof-checking enhancements to Nqthm-1992.
   For more information, contact Robert S. Boyer <boyer@cli.com>, J.
   Strother Moore <moore@cli.com>, or Matt Kaufmann <kaufmann@cli.com>,
   Computational Logic Inc., 1717 West 6th Street, Suite 290, Austin, TX
   78703-4776.  Send mail to nqthm-users-request@cli.com to be added to
   the mailing list.

   The Nuprl Proof Development System is available by anonymous ftp
   from ftp://ftp.cs.cornell.edu/pub/n/. Nuprl should run in any Common
   Lisp with CLX. There are also (obsolete) interfaces for Symbolics Lisp
   machines and Suns running the SunView window system. Nuprl has been
   tested with Allegro, Lucid, AKCL. For further information, contact
   Elizabeth Maxwell, <maxwell@cs.cornell.edu>, Nuprl Distribution
   Coordinator, Department of Computer Science, Upson Hall, Cornell
   University, Ithaca, NY 14853.

   Otter         -- ftp://info.mcs.anl.gov/pub/Otter/Otter-2.2/
                    anagram.mcs.anl.gov:/pub/Otter/
                    Contact: otter@mcs.anl.gov
                    Resolution-based theorem prover.

   RRL       -- ftp://herky.cs.uiowa.edu/public/ [128.255.28.100]
                Rewrite Rule Laboratory

   See SEQUEL entry in the Lisp FAQ, part 6. 

   SETHEO        -- ftp://flop.informatik.tu-muenchen.de/pub/fki/ [131.159.8.35]
                    Get the files setheo.info and setheo.tar.Z.
                    SETHEO (SEquential THEOrem prover) is an automated
                    theorem prover for formulae of predicate logic. 
                    SETHEO is based on the calculus of ``connection
                    tableaux''. SETHEO runs on Sun SPARCs only.  
                    Contact: setheo@informatik.tu-muenchen.de
                                
   XPNet (X Proof Net) is a graphical interface to proof nets with an
   efficient proof checker. It is available by anonymous ftp to
   ftp.cis.upenn.edu:/pub/xpnet.tar.Z [130.91.6.8]. For further
   information, write to Jawahar Chirimar <chirimar@saul.cis.upenn.edu>, 
   Carl A. Gunter <gunter@saul.cis.upenn.edu>, or Myra VanInwegen
   <myra@saul.cis.upenn.edu>.

Theorem Proving/Automated Reasoning (Problems):

   ATP Problems  -- anagram.mcs.anl.gov:/pub/ATP_Problems/*
                    Collection of ATP problems from Otter, CADE, and JAR.
                    The problems include algebra, analysis, circuits,
                    geometry, logic problems, Pelletier's problem set,
                    program verification, puzzles, set theory, and topology.

   The TPTP (Thousands of Problems for Theorem Provers) Problem Library
   is a collection of test problems for automated theorem provers (ATPs),
   using the clausal normal form of 1st order predicate logic.  The goal
   of the TPTP is to provide a firm basis for the testing, evaluation,
   and comparison of ATP systems through a comprehensive library of ATP
   test problems in a general purpose format. The TPTP includes tools to
   convert the problems to existing ATP formats, such as the OTTER, MGTP,
   PTTP, SETHEO, and SPRFN formats.  Each problem includes a list of
   references and other relevant information.  The TPTP also aims to
   supply general guidelines outlining the requirements for ATP system
   evaluation. The TPTP can be obtained by anonymous ftp from either the
   Department of Computer Science, James Cook University, Australia,

      ftp://coral.cs.jcu.edu.au/pub/research/tptp-library/   [137.219.17.4]

   or the Institut fuer Informatik, TU Muenchen, Germany,

      ftp://flop.informatik.tu-muenchen.de/pub/tptp-library/ [131.159.8.35]

   as the files ReadMe (general information about the library),
		TPTP-v1.1.0.tar.gz (the library itself), and
		TR-v1.0.0.ps.gz (a postscript technical report about the TPTP).
   The TPTP is also accessible through WWW using either of the URLs

      ftp://coral.cs.jcu.edu.au/users/GSutcliffe/WWW/
      http://wwwjessen.informatik.tu-muenchen.de/~suttner/tptp.html

   Additions and corrections may be sent to Geoff Sutcliffe
   <geoff@cs.jcu.edu.au> (Fax: +61-77-814029) or Christian Suttner
   <suttner@informatik.tu-muenchen.de> (Fax: +49-89-526502).  If you
   would like to be kept informed of new versions of the TPTP, please
   send email to either of them.

Truth Maintenance:

   The truth maintenance system and problem solver implementations
   described in the book "Building Problem Solvers" by Ken Forbus and
   Johan de Kleer are available by anonymous ftp from

      	multivac.ils.nwu.edu:/pub/BPS/
	parcftp.xerox.com:/pub/bps/ 

   For more information send mail to Johan de Kleer <deKleer@parc.xerox.com>.
   Send bug reports to bug-bps@ils.nwu.edu.