Thursday, 15 March 2007, 14:00
Cybernetica Bldg (Akadeemia tee 21), room B101
Slides from the talk [pdf]
Abstract: It is well-known that defining a labelled transition system is very difficult. Traditionally, LTSs are crafted "by hand", but the more complex is a calculus, the more difficult is to devise its LTS. In the last years, much work has been spent in looking for general procedures for deriving LTSs from reduction systems (which are easier to state). In this respect, an emerging meta-model are Milner's bigraphs, which allow to describe the evolutions of systems with locations and connections. Remarkably, these meta-models allow to derive a labelled transition system from a reaction system via a general construction, called "relative pullback". In this talk we will summarize the basic theory behind relative pullbacks, and present directed bigraphs, a generalization of original bigraphs, which allow to deal with more calculi than previous models.