Logics of Informational Interactions

The pre-eminence of logical dynamics, over a static and purely propositional view of Logic, lies at the core of a new understanding of both formal epistemology and the logical foundations of quantum mechanics. Both areas appear at first sight to be based on purely static propositional formalisms, but in our view their fundamental operators are essentially dynamic in nature. Quantum logic can be best understood as the logic of physically-constrained informational interactions (in the form of measurements and entanglement) between subsystems of a global physical system. Similarly, (multi-agent) epistemic logic is the logic of socially-constrained informational interactions (in the form of direct observations, learning, various forms of communication and testimony) between “subsystems” of a social system. Dynamic Epistemic Logic (DEL) provides us with a unifying setting in which these informational interactions, coming from seemingly very different areas of research, can be fully compared and analyzed. The DEL formalism comes with a powerful set of tools that allows us to make the underlying dynamic/interactive mechanisms fully transparent

A Closeness- and Priority-Based Logical Study of Social Network Creation

This paper is part of an on-going programme on the study of the logical aspects of social network formation. It recalls the so-called social network model, discussing the properties of a notion of closeness between agents (in terms of the number of traits they have in common); then introduces an extended social network model in which different agents might assign different values to different traits, discussing the properties of the notion of weighted closeness that arises. These notions are used to define social network creation operations by means of a threshold strategy. The paper studies the properties of the social networks the updates create, providing sound and complete axiom systems for formal languages describing these updates’ effects.publishedVersio

Post-grooming furunculose bij een hond

A five-year-old, intact, male labrador retriever was presented on emergency with general complaints of fever, lethargy and anorexia. During clinical examination, very painful skin lesions were noticed dorsally on the neck and back, and there was also a clear left apical systolic murmur with a degree of 4/6. On histopathological examination of the lesional skin, there was rupture of the follicle wall surrounded with a pronounced suppurative inflammation. The dog was diagnosed with post-grooming furunculosis and mitral valve endocardiosis ACVIM stage B2. Culture of the lesional skin and the shampoo used to wash the dog prior to the onset of the skin lesions revealed the presence of the same bacteria, evidencing a clear link between the bathing and development of the skin lesions