Logics of knowledge and action: critical analysis and challenges

International audienceWe overview the most prominent logics of knowledge and action that were proposed and studied in the multiagent systems literature. We classify them according to these two dimensions, knowledge and action, and moreover introduce a distinction between individual knowledge and group knowledge, and between a nonstrategic an a strategic interpretation of action operators. For each of the logics in our classification we highlight problematic properties. They indicate weaknesses in the design of these logics and call into question their suitability to represent knowledge and reason about it. This leads to a list of research challenges

Mycobacterium bovis endophthalmitis from BCG immunotherapy for bladder cancer

BACKGROUND: We report a patient who developed BCG endophthalmitis after BCG immunotherapy for bladder cancer. Comparison of this case with 2 other reported cases reveals a similar pattern of elderly, debilitated and immunocompromised patients with poor response to systemic antituberculous therapy in whom systemic steroids are used concurrently. Age and glucocorticoids are known to lead to thymic involution, reduce cell mediated immunity, and a lowering in the number of naive T cells capable of mounting an effective defense to new infectious agents. CONCLUSIONS: Physicians should be aware of the potential for ocular complications of BCG immunotherapy in the elderly, immunocompromised, on oral steroid

Playing Cards with Hintikka:An Introduction to Dynamic Epistemic Logic

This contribution is a gentle introduction to so-called dynamic epistemic logics, that can describe how agents change their knowledge and beliefs. We start with a concise introduction to epistemic logic, through the example of one, two and finally three players holding cards; and, mainly for the purpose of motivating the dynamics, we also very summarily introduce the concepts of general and common knowledge. We then pay ample attention to the logic of public announcements, wherein agents change their knowledge as the result of, indeed, public announcements. One crucial topic in that setting is that of unsuccessful updates: formulas that become false when announced. The Moore-sentences that were already extensively discussed at the conception of epistemic logic in [15] give rise to such unsuccessful updates. After that, we present a few examples of more complex epistemic updates. Our closing observations are on recent developments that link the ‘standard’ topic of (theory) belief revision [1] to the dynamic epistemic logics introduced here