Dynamic epistemic modelling

This paper introduces DEMO, a Dynamic Epistemic Modelling tool. DEMO llows modelling epistemic updates, graphical display of update results, graphical display of action models, formula evaluation in epistemic models, translation of dynamic epistemic formulas to PDL formulas, and so on. The paper implements a reduction of dynamic epistemic logic to PDL. The reduction of dynamic epistemic logic to automata PDL from Van Benthem and Kooi is also discussed and implemented. Epistemic models are minimized under bisimulation, and update action models are minimized under action emulation (the appropriate structural notion for having the same update effect). The paper is an exemplar of tool building for epistemic updatelogic. It contains the full code of an implementation in Haskell in `literate programming' style, of DEMO