Modules over monads and operational semantics (expanded version)

This paper is a contribution to the search for efficient and high-levelmathematical tools to specify and reason about (abstract) programming languagesor calculi. Generalising the reduction monads of Ahrens et al., we introducetransition monads, thus covering new applications such aslambda-bar-mu-calculus, pi-calculus, Positive GSOS specifications, differentiallambda-calculus, and the big-step, simply-typed, call-by-value lambda-calculus.Moreover, we design a suitable notion of signature for transition monads