  Process algebra and temporal logic are two popular paradigms for the
specification, verification and systematic development of reactive and
concurrent systems. These two approaches take different standpoint for looking
at specifications and verifications, and offer complementary advantages. In
order to mix algebraic and logic styles of specification in a uniform
framework, the notion of a logic labelled transition system (LLTS) has been
presented and explored by Luttgen and Vogler. This paper intends to propose a
LLTS-oriented process calculus which, in addition to usual process-algebraic
operators, involves logic connectives (conjunction and disjunction) and
standard temporal operators (always and unless). This calculus preserves usual
properties of these logic operators, allows one to freely mix operational and
logic operators, and supports compositional reasoning. Moreover, the links
between this calculus and Action-based Computation Tree Logic (ACTL) including
characteristic formulae of process terms, characteristic processes of ACTL
formulae and Galois connection are explored.
