Filters








327 Hits in 0.81 sec

O b i t u a r y Andrey V. Voronkov

2020 Archiv Euromedica  
Voronkov earned the respect and affection among colleagues. Andrey V. Voronkov was a versatile and talented man.  ...  Andrey Voronkov conducted numerous competitions and boxing matches attracting best professional boxers.  ... 
doi:10.35630/2199-885x/2020/10/4/obituary fatcat:sboabu3uhfasfpeygnqxdaovxq

Selecting the Selection [article]

Giles Reger, Martin Suda, Andrei Voronkov, Krystof Hoder
2016 arXiv   pre-print
Modern saturation-based Automated Theorem Provers typically implement the superposition calculus for reasoning about first-order logic with or without equality. Practical implementations of this calculus use a variety of literal selections and term orderings to tame the growth of the search space and help steer proof search. This paper introduces the notion of lookahead selection that estimates (looks ahead) the effect on the search space of selecting a literal. There is also a case made for
more » ... a case made for the use of incomplete selection functions that attempt to restrict the search space instead of satisfying some completeness criteria. Experimental evaluation in the \Vampire\ theorem prover shows that both lookahead selection and incomplete selection significantly contribute to solving hard problems unsolvable by other methods.
arXiv:1604.08055v1 fatcat:faa3oyfbzndkdcf4sjz5ry2xci

Coming to Terms with Quantified Reasoning [article]

Laura Kovacs, Simon Robillard, Andrei Voronkov
2016 arXiv   pre-print
We will not give a full proof of Theorem 2 but refer to (Korovin and Voronkov 2007) for details.  ...  Using the same reasoning as in (Korovin and Voronkov 2007) one can then prove the following result. Theorem 2.  ... 
arXiv:1611.02908v1 fatcat:gfxm4sj7prgcrdpl3ymffnhp4m

Knuth-Bendix constraint solving is NP-complete [article]

Konstantin Korovin, Andrei Voronkov
2002 arXiv   pre-print
Let us note that the problem of solvability of a Knuth-Bendix ordering constraints consisting of a single inequality can be solved in polynomial time [Korovin and Voronkov 2001] .  ...  In [Korovin and Voronkov 2001] we prove that the problem of solving Knuth-Bendix ordering constraints consisting of a single inequality can be solved in polynomial time.  ... 
arXiv:cs/0207068v1 fatcat:3nkk43lfzjfnxi4oewbwai2foi

Stratified Resolution [chapter]

Anatoli Degtyarev, Andrei Voronkov
2000 Lecture Notes in Computer Science  
A first version (Degtyarev and Voronkov, 2000) of this work appeared in the Proceedings of CADE-17.  ...  The proof of Degtyarev and Voronkov (2000) can also only handle special cases of redundancy criteria.  ... 
doi:10.1007/10721959_28 fatcat:fes7iqnuprfkpgbphjf4fv6nda

The Inverse Method for Many-Valued Logics [chapter]

Laura Kovács, Andrei Mantsivoda, Andrei Voronkov
2013 Lecture Notes in Computer Science  
We define an automatic proof procedure for finitely manyvalued logics given by truth tables. The proof procedure is based on the inverse method. To define this procedure, we introduce so-called introduction-based sequent calculi. By studying proof-theoretic properties of these calculi we derive efficient validity-and satisfiability-checking procedures based on the inverse method. We also show how to translate the validity problem for a formula to unsatisfiability checking of a set of
more » ... a set of propositional clauses. We acknowledge funding from the Austrian FWF grant S11410-N23 and the Austrian WWTF grant ICT C-050. Suppose that γ = s 1 , . . . , s m . Define the set C(γ) of clauses consisting of clauses of three kinds:
doi:10.1007/978-3-642-45114-0_2 fatcat:5nwikrulrrcynelpndcsn7jpry

Conflict Resolution [chapter]

Konstantin Korovin, Nestan Tsiskaridze, Andrei Voronkov
2009 Lecture Notes in Computer Science  
We introduce a new method for solving systems of linear inequalities over the rationals-the conflict resolution method. The method successively refines an initial assignment with the help of newly derived constraints until either the assignment becomes a solution of the system or a trivially unsatisfiable constraint is derived. We show that this method is correct and terminating. Our experimental results show that conflict resolution outperforms the Fourier-Motzkin method and the Chernikov
more » ... the Chernikov algorithm, in some cases by orders of magnitude.
doi:10.1007/978-3-642-04244-7_41 fatcat:zowplb5j6vcqtnp55fop6cg4ua

Playing with AVATAR [chapter]

Giles Reger, Martin Suda, Andrei Voronkov
2015 Lecture Notes in Computer Science  
Modern first-order resolution and superposition theorem provers use saturation algorithms to search for a refutation in clauses derivable from the input clauses. On hard problems, this search space often grows rapidly and performance degrades especially fast when long and heavy clauses are generated. One approach that has proved successful in taming the search space is splitting where clauses are split into components with disjoint variables and the components are asserted in turn. This reduces
more » ... turn. This reduces the length and weight of clauses in the search space at the cost of keeping track of splitting decisions. This paper considers the new AVATAR (Advanced Vampire Architecture for Theories And Resolution) approach to splitting which places a SAT (or SMT) solver at the centre of the theorem prover and uses it to direct the exploration of the search space. Using such an approach also allows the propositional part of the search space to be dealt with outside of the first-order prover. AVATAR has proved very successful, especially for problems coming from applications such as program verification and program analysis as these commonly contain clauses suitable for splitting. However, AVATAR is still a new idea and there is much left to understand. This paper presents an in-depth exploration of this new architecture, introducing new, highly experimental, options that allow us to vary the operation and interaction of the various components. It then extensively evaluates these new options, using the TPTP library, to gain an insight into which of these options are essential and how AVATAR can be optimally applied. Partially supported by the EPSRC grant "Reasoning for Verification and Security" AVATAR by Example Whilst the theory of AVATAR was established in [9] , and is reviewed later in this paper, the authors feel that the key ideas behind the approach are best demonstrated via an example.
doi:10.1007/978-3-319-21401-6_28 fatcat:qelxxzlrvbhjlmsujj6vxbewwu

Logic programming with bounded quantifiers [chapter]

Andrei Voronkov
1992 Lecture Notes in Computer Science  
doi:10.1007/3-540-55460-2_37 fatcat:ssekuzqmvvcczc2mozorbnlc2y

GoRRiLA and Hard Reality [chapter]

Konstantin Korovin, Andrei Voronkov
2012 Lecture Notes in Computer Science  
We call a theory problem a conjunction of theory literals and a theory solver any system that solves theory problems. For implementing efficient theory solvers one needs benchmark problems, and especially hard ones. Unfortunately, hard benchmarks for theory solvers are notoriously difficult to obtain. In this paper we present two tools: Hard Reality for generating theory problems from real-life problems with non-trivial boolean structure and GoRRiLA for generating random theory problems for
more » ... ry problems for linear arithmetic. Using GoRRiLA one can generate problems containing only a few variables, which however are difficult for all state-of-the-art solvers we tried. Such problems can be useful for debugging and evaluating solvers on small but hard problems. Using Hard Reality one can generate hard theory problems which are similar to problems found in reallife applications, for example, those taken from SMT-LIB [3] .
doi:10.1007/978-3-642-29709-0_21 fatcat:tn6odrawb5cbtored6zp6rkw54

Implementing Conflict Resolution [chapter]

Konstantin Korovin, Nestan Tsiskaridze, Andrei Voronkov
2012 Lecture Notes in Computer Science  
The conflict resolution method, introduced by the authors in [1] is a new method for solving systems of linear inequalities over the rational and real numbers. This paper investigates various heuristics for optimisation of the method and presents experimental evaluation. The method and heuristics are evaluated against various benchmarks and compared to other methods, such as the Fourier-Motzkin elimination method and the simplex method.
doi:10.1007/978-3-642-29709-0_31 fatcat:k5kqzuvm3rgollknsivel5tzke

Finding Finite Models in Multi-Sorted First Order Logic [article]

Giles Reger, Martin Suda, Andrei Voronkov
2016 arXiv   pre-print
Martin Suda and Andrei Voroknov were partially supported by ERC Starting Grant 2014 SYMCAR 639270. Andrei Voronkov was also partially supported by the Wallenberg Academy Fellowship 2014 -TheProSE.  ... 
arXiv:1604.08040v1 fatcat:3mwe45k45fb5lefbu53sfouupi

Interpolation and Symbol Elimination [chapter]

Laura Kovács, Andrei Voronkov
2009 Lecture Notes in Computer Science  
We prove several results related to local proofs, interpolation and superposition calculus and discuss their use in predicate abstraction and invariant generation. Our proofs and results suggest that symbol-eliminating inferences may be an interesting alternative to interpolation.
doi:10.1007/978-3-642-02959-2_17 fatcat:6e4pgxsbtvhn3ei2bnp4kdpnwm

Stratified resolution

Anatoli Degtyarev, Robert Nieuwenhuis, Andrei Voronkov
2003 Journal of symbolic computation  
A first version (Degtyarev and Voronkov, 2000) of this work appeared in the Proceedings of CADE-17.  ...  The proof of Degtyarev and Voronkov (2000) can also only handle special cases of redundancy criteria.  ... 
doi:10.1016/s0747-7171(03)00036-1 fatcat:f4pu7wm3jbgi5ov66xzkhya3de

Selecting the Selection [chapter]

Kryštof Hoder, Giles Reger, Martin Suda, Andrei Voronkov
2016 Lecture Notes in Computer Science  
Andrei Voronkov is also supported by the Wallenberg Foundation.  ... 
doi:10.1007/978-3-319-40229-1_22 fatcat:w2llu3k2qjffrduixn2n6i3lde
« Previous Showing results 1 — 15 out of 327 results