This article demonstrates how a powerful and expressive abstraction from concurrency theory plays a dual rôle as a programming tool for concurrent applications and as a foundation for their verification. This abstraction—monads of resumptions expressed using monad transformers—is cheap: it is easy to understand, easy to implement, and easy to reason about. We illustrate the expressiveness of th...

It is known that requiring a controlled system to be decoupled may increase costs in terms of some performance measures. However, decoupling may be desirable from an applied perspective. This paper gives an explicit quantiication of the costs of decoupling. In particular, the average quadratic tracking error is used to quantify performance. The analysis exploits the parametrisation of all decou...

Tupling is a well-known transformation tactic to obtain new recursive functions without redundant recursive calls and/or multiple traversals of common data, which is achieved by grouping some recursive functions into a tuple. Although being studied for a long time based on fold/unfold transformation, it su ers from the high cost of keeping track of function calls and has to use clever control t...