,
Sergey Goncharov
Creative Commons Attribution 3.0 Unported license
We introduce a new notion of "guarded Elgot monad", that is a monad equipped with a form of iteration. It requires every guarded morphism to have a specified fixpoint, and classical equational laws of iteration to be satisfied. This notion includes Elgot monads, but also further examples of partial non-unique iteration, emerging in the semantics of processes under infinite trace equivalence. We recall the construction of the "coinductive resumption monad" from a monad and endofunctor, that is used for modelling programs up to bisimilarity. We characterize this construction via a universal property: if the given monad is guarded Elgot, then the coinductive resumption monad is the guarded Elgot monad that freely extends it by the given endofunctor.
@InProceedings{levy_et_al:LIPIcs.CALCO.2019.13,
author = {Levy, Paul Blain and Goncharov, Sergey},
title = {{Coinductive Resumption Monads: Guarded Iterative and Guarded Elgot}},
booktitle = {8th Conference on Algebra and Coalgebra in Computer Science (CALCO 2019)},
pages = {13:1--13:17},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-120-7},
ISSN = {1868-8969},
year = {2019},
volume = {139},
editor = {Roggenbach, Markus and Sokolova, Ana},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.CALCO.2019.13},
URN = {urn:nbn:de:0030-drops-114414},
doi = {10.4230/LIPIcs.CALCO.2019.13},
annote = {Keywords: Guarded iteration, guarded monads, coalgebraic resumptions}
}