31,572 research outputs found
Operations on Fixpoint Equation Systems
Full text linkWe study operations on fixpoint equation systems (FES) over arbitrary complete lattices. We investigate under which conditions these operations, such as substituting variables by their definition, and swapping the ordering of equations, preserve the solution of a FES. We provide rigorous, computer-checked proofs. Along the way, we list a number of known and new identities and inequalities on extremal fixpoints in complete lattices
A Detailed Account of The Inconsistent Labelling Problem of Stutter-Preserving Partial-Order Reduction
Full text linkOne of the most popular state-space reduction techniques for model checking is partial-order reduction (POR). Of the many different POR implementations, stubborn sets are a very versatile variant and have thus seen many different applications over the past 32 years. One of the early stubborn sets works shows how the basic conditions for reduction can be augmented to preserve stutter-trace equivalence, making stubborn sets suitable for model checking of linear-time properties. In this paper, we identify a flaw in the reasoning and show with a counter-example that stutter-trace equivalence is not necessarily preserved. We propose a stronger reduction condition and provide extensive new correctness proofs to ensure the issue is resolved. Furthermore, we analyse in which formalisms the problem may occur. The impact on practical implementations is limited, since they all compute a correct approximation of the theory.peerReviewe
Infinite-data PBES Quotienting with the mCRL2 toolset
No full textThis folder contains the benchmarks that were performed as part of the publications
Thomas Neele, Tim A. C. Willemse, Jan Friso Groote:
Solving Parameterised Boolean Equation Systems with Infinite Data Through Quotienting.
FACS 2018. LNCS 11222, pp. 216-236.
and
Thomas Neele, Tim A. C. Willemse, Jan Friso Groote:
Finding Compact Proofs for Infinite-Data Parameterised Boolean Equation Systems.
Science of Computer Programming, FACS 2018 special issue. Accepted for publication.</p
Dataset with experiments for 'Partial-Order Reduction for Parity Games with an Application on Parameterised Boolean Equation Systems'
No full textThis archive contains the experiments that were performed as part of the publication
Thomas Neele, Tim A. C. Willemse, Wieger Wesselink: Partial-Order Reduction for Parity Games with an Application on Parameterised Boolean Equation Systems.
TACAS 2020 (accepted for publication).</p
Sussex, England 1810
No full textCadastral map. Shows land holdings of William Lambe, William Skrine, F.S. Blunt, Lord Erskine, Rev. Hy. Chatfield, Timoty Shelley, Thomas Shadwell, John Dennett, John Gatford, John Dungate and Thomas Jupp. "High Beech Estate," "Blackfold," "Snashalls and Highthorns."Grayscale;[ca. 1:9,800]. 12 chains in an inc
Infinite-data PBES Quotienting with the mCRL2 toolset
No full textThis folder contains the benchmarks that were performed as part of the publications Thomas Neele, Tim A. C. Willemse, Jan Friso Groote: Solving Parameterised Boolean Equation Systems with Infinite Data Through Quotienting. FACS 2018. LNCS 11222, pp. 216-236. and Thomas Neele, Tim A. C. Willemse, Jan Friso Groote: Finding Compact Proofs for Infinite-Data Parameterised Boolean Equation Systems. Science of Computer Programming (FACS 2018 special issue), vol. 188, 102389, 2020
Experiments for the paper "(Re)moving Quantifiers to Simplify Parameterised Boolean Equation Systems"
Full text linkThis archive contains files for experiments with quantifier elimination for parameterised Boolean equation systems, as described in the paper
Thomas Neele, (Re)moving Quantifiers to Simplify Parameterised Boolean Equation Systems, in ARQNL 2022, CEUR-WS.
Each folder contains an mCRL2 process specification, a modal mu-calculus formula and a bash script run.sh. To run the experiments, an installation of the mCRL2 tool set (version 202206.0 or newer) should be available in the PATH. Source code and binaries are available via https://mcrl2.org or https://github.com/mCRL2org/mCRL2.
The run scripts automatically generate a linear process (LPS) and a PBES. The latter is used to compare three approaches:
Not applying any constant elimination.
Applying the standard constant elimination algorithm from the paper "Static Analysis Techniques for Parameterised Boolean Equation Systems" by Simona Orzan, Wieger Wesselink and Tim A. C. Willemse.
Applying the quantifier analysis of the paper mentioned at the top.
In case of the motivating example, the resulting PBES for each approach is printed to stdout. For the ABP and cache coherence examples, the size of the underlying BES (called structure graph in the tools) is printed
Thomas Grisell letter to Thomas Rotch, 2nd mo 19th 1823
No full textThomas Grisell's letter reached the Rotch household several months before the unexpected death of Thomas Rotch in August, 1823. This is the last letter of the series and presumably the author learned of his friend's death before another letter was penned. 7.95" x 10" (20.2 by 25.5 cm
Replication package with proofs for the paper "Operations on Fixpoint Equation Systems"
No full text<p>This archive contains mechanized proofs for the theorems and lemmas that appear in the paper</p>
<blockquote>
<p>Operations on Fixpoint Equation Systems, Thomas Neele and Jaco van de Pol</p>
</blockquote>
<p>This package contains proofs in both <a href="https://coq.inria.fr/">Coq</a> and <a href="https://pvs.csl.sri.com/">PVS</a>. See the included README file for details on how to execute the proofs.</p>
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