Encoding many-valued logic in {\lambda}-calculus

We extend the well-known Church encoding of two-valued Boolean Logic in $\lambda$-calculus to encodings of $n$-valued propositional logic (for $3\leq n\leq 5$) in well-chosen infinitary extensions in $\lambda$-calculus. In case of three-valued logic we use the infinitary extension of the finite $\lambda$-calculus in which all terms have their B\"ohm tree as their unique normal form. We refine this construction for $n\in\{4,5\}$. These $n$-valued logics are all variants of McCarthy's left-sequential, three-valued propositional calculus. The four- and five-valued logic have been given complete axiomatisations by Bergstra and Van de Pol. The encodings of these $n$-valued logics are of interest because they can be used to calculate the truth values of infinitary propositions. With a novel application of McCarthy's three-valued logic we can now resolve Russell's paradox. Since B\"ohm trees are always finite in Church's original $\lambda{\mathbf I}$-calculus, we believe their construction to be within the technical means of Church. Arguably he could have found this encoding of three-valued logic and used it to resolve Russell's paradox.Comment: 15 page

Analyzing inter-organizational systems from a power and interest perspective

Inter-organizational systems (IOS) are ICT-based systems that enable organizations to share information and to electronically conduct business across organizational boundaries. Especially since the increasing availability of the Internet, there have been less technological barriers to implement IOS. However, that does not imply that IOS-possibilities are implemented successfully in all occasions: other barriers may remain. Innovation is not only a technical process of ?solving problems?, it also involves economic and political processes in which interests are articulated, alliances are built and outcomes are struggled over. To explore this observation, this paper presents a model that helps to describe and analyze IOS from a power and interest perspective of multiple parties. To illustrate this model, eight case studies of IOS are discussed, of which two in more depth. After that, we will put the findings of the analysis in a broader perspective. The paper concludes with the assertion that the scope for the design of an effective IOS depends on a combination of technical, economic and social

La ciudad en su contexto

Jan de Vries reflexiona sobre algunes de les claus per a una aproximació ampla a I'estudi del fenomen urba a I'Europa Modema. La urbanització demografica no és un episodi reductible a criteris de ritmes de creixement, sinb a I'anilisi dels condicionants que impliquen la seva ubicació espaial. L'historiador ha de defugir els plantejaments teleolbgics que I'obstaculitzin per a comprendre I'extraordinhia realitat de la urbanització histbrica al mateix temps que ha d'emprendre I'analisi del paper desenvolupat per les ciutats en I'el~laboració i reforq de la cultura dominant. Aquesta perspectiva permet reivindicar la persistkncia d'un protagonisme econbmic, social, polític i cultural i defugir la minimització del paper de la ciutat al de mera unitat administrativa dins I'estat.Jan de Vries reflects on the study of urban phenomenon in the Early Modem Europe, considering that demographic urbanization can not be reducted to different approaches about the rythms of growth but to the analysis of the determining factors that involved its spatial location. Historians must escape from teleological theories that are an obstacle to understand the reality of the historical urbanization and they have to focus their analysis on the role developed by cities in the construction of the dominant culture. De Vries' perspective permits to vindicate the persistence of the economic, social, political and cultural leading role of cities and to elude the tendency to consider cities as mere administrative unities in a state

Logistiek organiseren. Een studie naar de relatie tussen goederenstroombesturing en logistieke organisatie.

Doel van deze studie was om te komen tot een referentiekader van waaruit zowel beschrijvende, analyserende, als voorschrijvende uitspraken gedaan kunnen worden met betrekking tot de organisatorische inbedding van de goederenstroombesturing. De rechtvaardiging voor deze studie is gelegen in een theoretische en een praktische onvrede over de bestaande inzichten rond goederenstroombesturing. Vanuit de bedrijfskundige wetenschap gezien is het ontbreken van duidelijke 'body of knowledge' rond de vraag naar de organisatorische vormgeving en inbedding van de goederenstroombesturing een belangrijke drijfveer voor deze studie geweest. Vanuit de praktijk bezien is het vooral het onvermogen van de uiteenlopende wetenschappelijke denkrichtingen om logistieke organisatievraagstukken in praktisch handelen te vertalen, aanleiding geweest voor een meer diepgaande studie naar de organisatorische context van goederenstroombesturing. ... Zie: Samenvatting

Identifying inventory project management conflicts:Results of an empirical study

Although conflicts are being studied in many different management fields there seems to be a rather restricted number of studies on inventory management-related conflicts and it is for this reason why we conducted a study on exploring the different types of conflicts, their causes and the emerging character of conflicts during the shaping, implementation and usage of inventory systems. In doing so, a framework for assessing different types of conflicts is taken as a starting point. From our case studies, it can be concluded that each of the archetypical conflicts addressed in our framework manifested itself in the companies studied. Our exploratory case studies strongly indicates that during the process of redesigning and implementing improvements inventory management conflicts can evolve in time. Furthermore, in almost all companies studied, the identified conflicts had a multidimensional character and were a mix of the archetypes addressed in our theoretical framework. For project managers it seems to be important to be aware of the different potential conflicts that might arise during the course of inventory projects. The results presented in this article may therefore help project managers to guide projects in the area of inventory management more effectively