Abstract
The order-enriched category of monotonic predicate transformers over posets is a model of the refinement calculus of higher order imperative programs and pre-post specifications. This category is shown to be equivalent to the category of spans over ideal relations, and ideal relations are shown to be spans over monotonic functions between posets. To do this we use a skew span construction because the standard categorical span constructions are inapplicable. Axioms are given for products and coproducts of underlying posets as well as the homset as a coexponent, using inequations (for various kinds of lax adjunctions) and conditional equations (for adjunctions in subcategories) that are shown to uniquely determine the structures. The model is described in elementary terms using power allegories, an axiomatic calculus of relations, which makes the proofs accessible to non-specialists and shows that the results generalize to other base categories.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.