Towards a Symbolic Modal Logic for LOTOS

We present a version of HML [7], adapted to allow description of properties of Full LOTOS [8] specifications using symbolic values and conditions in modal formulae as well as concrete data values. In modifying HML we especially consider the features of LOTOS which distinguish it from other process algebras and discuss how these alter the requirements of the logic, and how this in turn is reflected in the semantics of the logic. Our logic is given in relation to a late symbolic semantics for Full LOTOS, clearly separating the process reasoning from the data reasoning. This work is motivated by our experiences of using LOTOS in several different applications [10, 15], in which we have identified a clear need for temporal reasoning about symbolic, and possibly partial, LOTOS specifications.