We present an abstract framework for concurrent processes in which atomic steps have
generic side effects, handled according to the principle of monadic encapsulation of effects.
Processes in this framework are potentially infinite resumptions, modelled using final
coalgebras over the monadic base. As a calculus for such processes, we introduce a
concurrent extension of Moggiʼs monadic meta-language of effects. We establish
soundness and completeness of a natural equational axiomatization of this calculus. Our …