A Parametrized Propositional Dynamic Logic with Application to Service Synthesis

We extend propositional dynamic logic (PDL) with variables ranging over an infinite domain. This extension, called parametrized PDL or PPDL for short, is interpreted over parametrized transitions systems whose edges are labeled with letters or variables and whose states are labeled with non-parametrized propositions. We show that the satisfiability problem for PPDL is decidable. We apply these results to the composition problem of web services in presence of constraints on the global ordering of the message-exchange events between the agents. We express the client specification and the available services as parametrized transitions systems and we express the behavioral constraints as a PPDL formula that the generated orchestrator must fulfill. It turns out that the model of such a formula represents the desired orchestrator.