CADE 2007


Non-Theorems, Non-Validity, Non-Provability

Bremen, Germany, Monday July 16, 2007

[ Text Version of the CFP ]

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

Invited Speakers

Alessandro Cimatti, IRST, Trento, (shared with CFV and VERIFY)
Koen Claessen, Chalmers University of Technology, Göteborg, (abstract)
Cesare Tinelli, University of Iowa, (shared with CFV and VERIFY) (abstract)

Workshop Schedule and Programme (Tentative)

09:00 - 11:00
1st Session: joint with CFV and VERIFY
09:00 - 10:00
Invited Talk
Cesare Tinelli
Trends and Challenges in Satisfiability Modulo Theories
10:00 - 11:00
Invited Talk
Alessandro Cimatti
Satisfiability Modulo the Theory of Bit Vectors
11:00 - 11:30
11:30 - 12:30
2nd Session: joint with VERIFY
11:30 - 12:00 Alan Bundy
Where's My Stuff? An Ontology Repair Plan
12:00 - 12:30 Philipp Rümmer
A Sequent Calculus for Integer Arithmetic
with Counterexample Generation

12:30 - 14:00
14:00 - 15:30
3rd Session
14:00 - 15:00
Invited Talk
Koen Claessen
A Paradigm Shift in ATP:
Towards Model-based Reasoning Systems
15:00 - 15:30 Jan Otop
Solution to some right alternative ring problems
15:30 - 16:00
16:00 - 17:30
4th Session
16:00 - 16:30 Didier Galmiche, Dominique Larchey-Wendling and Yakoub Salhi
Provability and Countermodels in Gödel-Dummett Logics
16:30 - 17:00 Arjeh M. Cohen, Jan Willem Knopper, and Scott H. Murray
Automatic Proof of Graph Nonisomorphism
17:00 - 17:30 Hans de Nivelle
Redundancy for Geometric Resolution

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,
approximate 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

This the 4th DISPROVING workshop, following the workshops at IJCAR 2004, CADE 2005, and FLoC 2006.

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 (Co-Chair)
Franz Baader
Peter Baumgartner (Co-Chair)
Simon Colton
Christian Fermüller
Bernhard Gramlich
William McCune
Hans de Nivelle (Co-Chair)
Michael Norrish
Silvio Ranise
Renate Schmidt
Carsten Schürmann
Graham Steel


Submissions should not exceed 10 pages.

Submission will be electronic only, using EasyChair. Here is the electronic submission page .

The deadline for submission is 25th of May 2007.


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.

Together with the organisers of the VERIFY'07 workshop at CADE, we are planing a joint journal special issue on the topics of both workshops. Authors of papers presented at DISPROVING and VERIFY will be welcome to submit extended and revised versions of their papers. However, contributions will not be limited to those based on papers presented at either workshops; other submission are welcome as well.

Workshop Venue

The workshop will be held on July 16, as part of
CADE 2007 (Conference on Automated Deduction),
International University Bremen,
July 17 - 20, 2007

Program & Workshop Chairs

Wolfgang Ahrendt
Chalmers University of Technology, Göteborg, Sweden
Email: ahrendt AT

Peter Baumgartner
National ICT Australia, Logic and Computation Program, Canberra, Australia
Email: Peter DOT Baumgartner AT

Hans de Nivelle
Institute for Computer Science, University of Wroclaw, Poland
Email: nivelle AT

Important Dates

May 25: paper submissions deadline
June 12: notification of acceptance
June 22: final version due
Monday, July 16: workshop date


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