Residual Nominal Automata

Joshua Moerman, Matteo Sammartino

Research output: Chapter in Book/Report/Conference proceedingConference contribution


We are motivated by the following question: which nominal languages admit an active learning algorithm? This question was left open in previous work, and is particularly challenging for languages recognised by nondeterministic automata. To answer it, we develop the theory of residual nominal automata, a subclass of nondeterministic nominal automata. We prove that this class has canonical representatives, which can always be constructed via a finite number of observations. This property enables active learning algorithms, and makes up for the fact that residuality – a semantic property – is undecidable for nominal automata. Our construction for canonical residual automata is based on a machine-independent characterisation of residual languages, for which we develop new results in nominal lattice theory. Studying residuality in the context of nominal languages is a step towards a better understanding of learnability of automata with some sort of nondeterminism.
Original languageEnglish
Title of host publicationLIPCs
Place of PublicationGermany
PublisherSchloss Dagstuhl- Leibniz-Zentrum fur Informatik GmbH, Dagstuhl Publishing
Number of pages21
ISBN (Electronic)978-3-95977-160-3
Publication statusPublished - 26 Aug 2020
Event31st International Conference on Concurrency Theory -
Duration: 1 Sept 20204 Sept 2020


Conference31st International Conference on Concurrency Theory
Abbreviated titleCONCUR

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