Projection Views of Register Automata

Register automata have been used as a convenient model for specifying and verifying database driven systems. An important problem in such systems is to provide views that hide or restructure certain information about the data or process, extending classical notions of database views. In this paper we carry out a formal investigation of views of register automata by considering simple views that project away some of the registers. We show that classical register automata are not able to describe such projections and introduce more powerful register automata that are able to do so. We also show useful properties of these automata such as closure under projection and decidability of verifying temporal properties of their runs.