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Refinement for Monadic Programs

We provide a framework for program and data refinement in Isabelle/HOL. The framework is based on a nondeterminism-monad with assertions, i.e., the monad carries a set of results or an assertion failure. Recursion is expressed by fixed points. For convenience, we also provide while and foreach combinators. The framework provides tools to automatize canonical tasks, such as verification condition generation, finding appropriate data refinement relations, and refine an executable program to a form that is accepted by the Isabelle/HOL code generator. Some basic usage examples can be found in this entry, but most of the examples and the userguide have been moved to the Collections AFP entry. For more advanced examples, consider the AFP entries that are based on the Refinement Framework.