We prove the syntactic soundness of classical tableaux with free variables and on-the-fly Skolemization. Soundness proofs are usually built from semantic arguments, and this is to our knowledge, the first proof that appeals to syntactic means. We actually prove the soundness property with respect to cut-free sequent calculus. This requires great care because of the additional liberty in freshne...

With the increasing use of automatic transformations of models, the correctness of these transformations becomes an increasingly important issue. Especially for model transformation generally defined using abstract description techniques like graph transformations or declarative relational specifications, however, establishing the soundness of those transformations by test-based approaches is n...

infinite dilution activity coefficients have been measured for seven binary systems at three different pressures using a newly - designed ebulliometer. the results obtained through these experimental measurements have been compared to literature values for four of the seven binary systems and the calculated deviation has been less than five percent in most cases. having verified the soundness a...

Shuffling is an effective method to build a publicly verifiable mix network to implement verifiable anonymous channels that can be used for important cryptographic applications like electronic voting and electronic cash. One shuffling scheme by Groth is claimed to be secure and efficient. However, its soundness has not been formally proven. An attack against the soundness of this shuffling sche...

Many logical methods are usually considered suitable to express the static properties of security protocols while unsuitable to model dynamic processes or properties. However, a security protocol itself is in fact a dynamic process over time, and sometimes it is important to be able to express time-dependent security properties of protocols. In this paper, we present a new timed logic based on ...

Many software applications are based on collaborating, yet competing, agents or virtual organisations exchanging services. Contracts, expressing obligations, permissions and prohibitions of the different actors, can be used to protect the interests of the organisations engaged in such service exchange. However, the potentially dynamic composition of services with different contracts, and the co...

This paper introduces a cohesion metric that can be used for the identification of weakly cohesive activities in a workflow design. Also, a heuristic is presented that is based on this cohesion metric to decide between various workflow design alternatives. Both a theoretical and an empirical evaluation give a positive support its soundness. The inspiration for the introduced notion is derived f...

This paper presents the notion of AND-OR reduction, which reduces a WF net to a smaller net by iteratively contracting certain well-formed subnets into single nodes until no more such contractions are possible. This reduction can reveal the hierarchical structure of a WF net, and since it preserves certain semantical properties such as soundness, it can help with analysing and understanding why...

Small and Medium Enterprises (SME) is an enterprise activity that plays a role in increasing national income, promoting economic growth, achieving stability. SMEs have promoted growth by creating employment opportunities balancing the economy. The increase number of has positively impacted Indonesian economy, showing overall 60.43 %, government being asked to reduce SME tax 0.5%. Unfortunately,...