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Testing Generalised Freeness of Words Gawrychowski, Pawel Manea, Florin Nowotka, Dirk Stringology Pattern matching Repetition Pseudo-repetition Pseudo-repetitions are a natural generalisation of the classical notion of repetitions in sequences: they are the repeated concatenation of a word and its encoding under a certain morphism or antimorphism (anti-/morphism, for short). We approach the problem of deciding efficiently, for a word w and a literal anti-/morphism f, whether w contains an instance of a given pattern involving a variable x and its image under f, i.e., f(x). Our results generalise both the problem of finding fixed repetitive structures (e.g., squares, cubes) inside a word and the problem of finding palindromic structures inside a word. For instance, we can detect efficiently a factor of the form xx^Rxxx^R, or any other pattern of such type. We also address the problem of testing efficiently, in the same setting, whether the word w contains an arbitrary pseudo-repetition of a given exponent. Schloss Dagstuhl – Leibniz-Zentrum für Informatik Pawel Gawrychowski and Florin Manea and Dirk Nowotka 2014 Is Part Of LIPIcs, Volume 25, 31st International Symposium on Theoretical Aspects of Computer Science (STACS 2014) InProceedings Text doc-type:ResearchArticle publishedVersion application/pdf doi:10.4230/LIPIcs.STACS.2014.337 urn:nbn:de:0030-drops-44694 https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.STACS.2014.337 eng https://creativecommons.org/licenses/by/3.0/legalcode