Effect Polymorphism in Higher-Order Logic

Andreas Lochbihler

5 May 2017


The notion of a monad cannot be expressed within higher-order logic (HOL) due to type system restrictions. We show that if a monad is used with values of only one type, this notion can be formalised in HOL. Based on this idea, we develop a library of effect specifications and implementations of monads and monad transformers. Hence, we can abstract over the concrete monad in HOL definitions and thus use the same definition for different (combinations of) effects. We illustrate the usefulness of effect polymorphism with a monadic interpreter for a simple language.
BSD License

Change history

[2018-02-15] added further specifications and implementations of non-determinism; more examples (revision bc5399eea78e)

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