{"title":"On periodically iterated morphisms","authors":"J. Endrullis, D. Hendriks","doi":"10.1145/2603088.2603152","DOIUrl":null,"url":null,"abstract":"We investigate the computational power of periodically iterated morphisms, also known as D0L systems with periodic control; we call them PerD0L systems for short. These systems give rise to a class of one-sided infinite sequences, called PerD0L words. We construct a PerD0L word with exponential subword complexity, thereby answering a question raised by Lepistö [23] on the existence of such words. We solve another open problem concerning the decidability of the first-order theories of PerD0L words [24]; we show it is already undecidable whether a certain letter occurs in a PerD0L word.","PeriodicalId":20649,"journal":{"name":"Proceedings of the Joint Meeting of the Twenty-Third EACSL Annual Conference on Computer Science Logic (CSL) and the Twenty-Ninth Annual ACM/IEEE Symposium on Logic in Computer Science (LICS)","volume":"24 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2012-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"4","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Proceedings of the Joint Meeting of the Twenty-Third EACSL Annual Conference on Computer Science Logic (CSL) and the Twenty-Ninth Annual ACM/IEEE Symposium on Logic in Computer Science (LICS)","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1145/2603088.2603152","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 4
Abstract
We investigate the computational power of periodically iterated morphisms, also known as D0L systems with periodic control; we call them PerD0L systems for short. These systems give rise to a class of one-sided infinite sequences, called PerD0L words. We construct a PerD0L word with exponential subword complexity, thereby answering a question raised by Lepistö [23] on the existence of such words. We solve another open problem concerning the decidability of the first-order theories of PerD0L words [24]; we show it is already undecidable whether a certain letter occurs in a PerD0L word.