Evidence for Fixpoint Logic

For many modal logics, dedicated model checkers offer diagnostics (e.g., counterexamples) that help the user understand the result provided by the solver. Fixpoint logic offers a unifying framework in which such problems can be expressed and solved, but a drawback of this framework is that it lacks comprehensive diagnostics generation. We extend the framework with a notion of evidence, which can be specialized to obtain diagnostics for various model checking problems, behavioural equivalence and refinement checking problems. We demonstrate this by showing how our notion of evidence can be used to obtain diagnostics for the problem of deciding stuttering bisimilarity. Moreover, we show that our notion generalizes the existing notions of counterexample and witness for LTL and ACTL* model checking

A process algebra with global variables

In standard process algebra, parallel components do not share a common state and communicate through synchronisation. The advantage of this type of communication is that it facilitates compositional reasoning. For modelling and analysing systems in which parallel components operate on shared memory, however, the communication-through-synchronisation paradigm is sometimes less convenient. In this paper we study a process algebra with a notion of global variable. We also propose an extension of Hennessy-Milner logic with predicates to test and set the values of the global variables, and prove correspondence results between validity of formulas in the extended logic and stateless bisimilarity and between validity of formulas in the extended logic without the set operator and state-based bisimilarity. We shall also present a translation from the process algebra with global variables to a fragment of mCRL2 that preserves the validity of formulas in the extended Hennessy-Milner logic.Comment: In Proceedings EXPRESS/SOS 2020, arXiv:2008.1241

Is the level of eye-hand coordination and executive functioning related to performance in para table tennis players? – An explorative study

The goal of this explorative study was to explore whether eye-hand coordination and executive functions (i.e. cognitive flexibility, attention control and information processing) are related to the performance level in para table tennis players. The data of 11 elite (age 15-54) and 11 non-elite para table tennis players (age 13-49) were analyzed. The results showed that the elite players performed better than the median norm values for cognitive flexibility and attention control while the non-elite players demonstrated slower information processing than the median norm values (p 1000 points scored ≥ 24 catches per 30 s in the eye hand coordination task, whereas the players with 1000 and < 1000 rating scores in the executive functions tests. The results present a first profile of para table tennis players regarding their eye-hand coordination and executive functions and the relationship of these constructs with the performance level. Long-term international cooperation is recommended to understand the value of the measured constructs to predict future successes

Modelling and analysing software in mCRL2

Model checking is an effective way to design correct software.Making behavioural models of software, formulating correctness properties using modal formulas, and verifying these using finite state analysis techniques, is a very efficient way to obtain the required insight in the software. We illustrate this on four common but tricky examples

Expressiveness and Completeness in Abstraction

We study two notions of expressiveness, which have appeared in abstraction theory for model checking, and find them incomparable in general. In particular, we show that according to the most widely used notion, the class of Kripke Modal Transition Systems is strictly less expressive than the class of Generalised Kripke Modal Transition Systems (a generalised variant of Kripke Modal Transition Systems equipped with hypertransitions). Furthermore, we investigate the ability of an abstraction framework to prove a formula with a finite abstract model, a property known as completeness. We address the issue of completeness from a general perspective: the way it depends on certain abstraction parameters, as well as its relationship with expressiveness.Comment: In Proceedings EXPRESS/SOS 2012, arXiv:1208.244

Anthropometric Characteristics, Physical Fitness and Motor Coordination of 9 to 11 Year Old Children Participating in a Wide Range of Sports

ObjectivesThe aim of this study was to investigate to what extent 9 to 11 year old children participating in a specific sport already exhibit a specific anthropometric, physical fitness and motor coordination profile, in line with the requirements of that particular sport. In addition, the profiles in children with a different training volume were compared and possible differences in training hours per week between children from a low, moderate, and high level of physical fitness and motor coordination were investigated.Methods and resultsData of 620 children, 347 boys and 273 girls, who participated in the Flemish Sports Compass were used. Only the primary sport of each child was considered and six groups of sports (Ball sports, Dance, Gymnastics, Martial arts, Racquet sports and Swimming) were formed based on common characteristics. Measurements consisted of 17 tests. Independent T-tests and Mann-Whitney U-tests revealed few differences between the groups of sports and the discriminant analyses with the moderate and low active group did not show any significant results (p > .05). However, when discriminating among the high active children, a 85.2 % correct classification between six groups of sports was found (Wilks' Λ = .137 and p DiscussionThe study showed that in general, children at a young age do not exhibit sport-specific characteristics, except in children with a high training volume. It is possible that on the one hand, children have not spent enough time yet in their sport to develop sport-specific qualities. On the other hand, it could be possible that they do not take individual qualities into account when choosing a sport

Comparative analysis of Ig and TCR gene rearrangements at diagnosis and at elapse of childhood precursor-B–ALL provides improved strategies for selection of stable PCR targets for monitoring of minimal residual disease

Immunoglobulin (Ig) and T-cell receptor (TCR) gene rearrangements are excellent patient-specific polymerase chain reaction (PCR) targets for detection of minimal residual disease (MRD) in acute lymphoblastic leukemia (ALL), but they might be unstable during the disease course. Therefore, we performed detailed molecula

Off-the-shelf automated analysis of liveness properties for just paths

We enrich the operational semantics of a simple process calculus with ACP-style communication with a concurrency relation, so that for every process expression there exists an associated notion of just path. We then present sufficient conditions on the communication function and the syntax of process expressions that facilitate the formulation of justness on the level of labels rather than on individual transitions, taking a designated set of signals into account. This paves the way for the formulation of liveness properties under justness assumptions in the modal μ-calculus and their verification on process specifications with the mCRL2 toolset

Modelling and analysing ERTMS hybrid level 3 with the mCRL2 toolset

\u3cp\u3eERTMS Hybrid Level 3 is a recent proposal for a train control system specification that serves to increase the capacity of the railway network by allowing multiple trains with an integrity monitoring system and a GSM-R connection to the trackside on a single section. In this paper we model the principles of ERTMS Hybrid Level 3 in the mCRL2 process algebra and perform an analysis with its associated toolset. Our analysis has resulted in suggestions for improvement of the principles that will be taken into account in the next version of the specification.\u3c/p\u3

Modelling and analysing ERTMS hybrid level 3 with the mCRL2 toolset

ERTMS Hybrid Level 3 is a recent proposal for a train control system specification that serves to increase the capacity of the railway network by allowing multiple trains with an integrity monitoring system and a GSM-R connection to the trackside on a single section. In this paper we model the principles of ERTMS Hybrid Level 3 in the mCRL2 process algebra and perform an analysis with its associated toolset. Our analysis has resulted in suggestions for improvement of the principles that will be taken into account in the next version of the specification