A complete axiomatisation of branching bisimulation for process algebras with alternative quantification over data

We define a class of process algebras with silent step and a generalised operation $gsum{$ that allows explicit treatment of emph{alternative quantification over data, and we investigate the specific subclass formed by the algebras of finite processes modulo rooted branching bisimulation. We give a ground complete axiomatisation for those branching bisimulation algebras of which the data part has built-in equality and Skolem functions.