Workshop on Disproving -
Non-Theorems, Non-Validity, Non-Provability

Tallinn, Estonia
Friday morning, July 22, 2005

The workshops DISPROVING and ESCAR are scheduled such that you can attend both.
DISPROVING fills the morning, whereas ESCAR starts in the afternoon.
The only overlap in time is the shared invited talk, taking place right after lunch.

[ Text Version of the CFP ]

Quick links:
[ Background, Scope, Topics, Workshop Goal, Audience  |  Invited Speakers  |  Technical Programme  |  Programme Committee  |  Submission  |  Publication  |  Workshop Venue  |  Workshop Organisers  |  Important Dates  |  Links ]

Invited Speakers

Byron Cook, Microsoft Research, Cambridge. (last talk of the workshop, shared with the ESCAR workshop)
Jürgen Giesl, RWTH Aachen. (first talk of the workshop)

Technical Programme

09:00-10:00    Disproving Termination of Term Rewriting
Jürgen Giesl, Invited Talk

10:00-10:30    Coffee break

10:30-11:00    Validated Construction of Congruence Closures
Aaron Stump
11:00-11:30    Correction of faulty conjectures and programs extraction
Moussa Demba, Francis Alexandre, and Khaled Bsaies

11:30-11:45    short break

11:45-12:15    Disproving Distributivity in Lattices Using Geometric Logic
Marc Bezem
12:15-12:45    Generating Counterexamples for Java Dynamic Logic
Philipp Rümmer

12:45-14:00    Lunch break

14:00-15:00    Automatic Theorem Proving for Program Verification Engines
Byron Cook, Invited Talk (shared with ESCAR)

Proceedings and Abstracts


Automated Reasoning (AR) traditionally has focused on proving theorems. Because of this, AR methods and tools in the past were mostly applied to formulae which were already known to be true. If on the other hand a formula is not a theorem, then most traditional AR methods and tools cannot handle this properly (i.e. they will fail, run out of resources, or simply not terminate). The opposite of proving, which we call disproving, particularly aims at identifying non-theorems, i.e. showing non-validity resp. non-provability, and providing some kind of proof of non-validity (non-provability). The proof for example could be a counter model, or an instantiation making the formula false.


In the scope of the workshop is every method that is able to discover non-theorems and, ideally, provides explanation why the formula is not a theorem. Possible subjects are decision procedures, model generation methods, reduction to SAT, formula simplification methods, abstraction based methods, failed-proof analysis.

Topics of relevance to the workshop therefore include

disproving conjectures in general,
extending standard proving methods with disproving capabilities,
approximative methods for identifying non-theorems,
counterexample generation,
counter model generation,
finite model generation,
decision procedures,
failure analysis,
reparation of non-theorems,
heuristics that help in identifying non-theorems,
applications and system descriptions.

Workshop Goal

The disproving workshops are intended as a platform for the exchange of ideas between researchers concerned with disproving in the broad sense. By discussing approaches across the different AR sub-communities, the workshop can identify common problems and solutions. Another goal is to elaborate known, and discover unknown, connections between other areas and disproving. Also, the meeting can enable an exchange of interesting examples for non-theorems. A long term goal is that the workshop series contributes to forming a disproving community within AR, and gives the work on disproving a greater visibility.


Non-theorems are an issue wherever one tries to prove statements which are not known to be valid in advance. Therefore, we aim at researchers from all areas of automated reasoning. The issue of the workshop is particularly relevant for all logics, calculi, and proving paradigms where non-validity is not covered by the (plain versions of) standard methods. This includes (but is not restricted to) first-order logic proving, inductive theorem proving, rewriting based reasoning, higher-order logic proving, logical frameworks, and special purpose logics like for instance program logics. We also target at the model generation community.

Beside mature work, we also solicit preliminary work or work in progress to be presented.

Programme Committee

Wolfgang Ahrendt (Organiser)
Peter Baumgartner (Organiser)
Johan Bos
Christian Fermüller
Ulrich Furbach
Bernhard Gramlich
Bill McCune
Hans de Nivelle (Organiser)
Harald Rueß
Renate Schmidt
Carsten Schürmann
Graham Steel
Cesare Tinelli
Andrei Voronkov
Calogero Zarba


Submissions should not exceed 10 pages.

Please use the electronic submission page .

The submission procedure will be electronic only, and only PDF files are acceptable.

The deadline for submission has been extended to the 9th of May 2005.


The final versions of the selected contributions will be collected in a volume to be distributed at the workshop and made accessible on the web.

The organisers plan for a special issue of the Nordic Journal of Computing, based on extended versions of selected workshop papers, but open to non-participants, in all cases with fresh reviewing. The decision of whether to do so will be taken after the workshop. (The according post proceedings of last years workshop are soon to appear within ENTCS.)

Workshop Venue

The workshop will be held on July 22 as part of
CADE-20 (20th International Conference on Automated Deduction),
Tallinn, Estonia
22 July - 27 July, 2005.

Workshop Organisers

Wolfgang Ahrendt
Chalmers University of Technology, Göteborg, Sweden

Peter Baumgartner
MPI für Informatik, Saarbrücken, Germany

Hans de Nivelle
MPI für Informatik, Saarbrücken, Germany

Important Dates

May 9: paper submissions deadline
June 3: notification of acceptance
June 26: final versions due
Friday, July 22: workshop date


For further information on the workshop, please contact one of the organisers.

Last modified: Fri Jul 1 18:09:45 CEST 2005