{"title":"The Well Structured Problem for Presburger Counter Machines","authors":"A. Finkel, Ekanshdeep Gupta","doi":"10.4230/LIPIcs.FSTTCS.2019.41","DOIUrl":"https://doi.org/10.4230/LIPIcs.FSTTCS.2019.41","url":null,"abstract":"We introduce the well structured problem as the question of whether a model (here a counter machine) is well structured (here for the usual ordering on integers). We show that it is undecidable for most of the (Presburger-defined) counter machines except for Affine VASS of dimension one. However, the strong well structured problem is decidable for all Presburger counter machines. While Affine VASS of dimension one are not, in general, well structured, we give an algorithm that computes the set of predecessors of a configuration; as a consequence this allows to decide the well structured problem for 1-Affine VASS.","PeriodicalId":175000,"journal":{"name":"Foundations of Software Technology and Theoretical Computer Science","volume":"86 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122563239","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Deciding Probabilistic Simulation between Probabilistic Pushdown Automata and Finite-State Systems","authors":"Hongfei Fu, J. Katoen","doi":"10.4230/LIPIcs.FSTTCS.2011.445","DOIUrl":"https://doi.org/10.4230/LIPIcs.FSTTCS.2011.445","url":null,"abstract":"This paper studies the decidability and computational complexity of checking probabilistic simulation pre-order between probabilistic pushdown automata (pPDA) and (probabilistic)finite-state systems. \u0000We show that checking classical and combined probabilistic similarity are EXPTIME-complete in both directions and become polynomial if both the number of control states of the pPDA and the size of the finite-state system are fixed. These results show that checking probabilistic similarity is as hard as checking similarity \u0000in the standard, i.e., non-probabilistic setting.","PeriodicalId":175000,"journal":{"name":"Foundations of Software Technology and Theoretical Computer Science","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124232139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Query Preserving Watermarking Schemes for Locally Treelike Databases","authors":"A. Chattopadhyay, M. Praveen","doi":"10.4230/LIPIcs.FSTTCS.2019.36","DOIUrl":"https://doi.org/10.4230/LIPIcs.FSTTCS.2019.36","url":null,"abstract":"Watermarking is a way of embedding information in digital documents. Much research has been done on techniques for watermarking relational databases and XML documents, where the process of embedding information shouldn't distort query outputs too much. Recently, techniques have been proposed to watermark some classes of relational structures preserving first-order and monadic second order queries. For relational structures whose Gaifman graphs have bounded degree, watermarking can be done preserving first-order queries. \u0000We extend this line of work and study watermarking schemes for other classes of structures. We prove that for relational structures whose Gaifman graphs belong to a class of graphs that have locally bounded tree-width and is closed under minors, watermarking schemes exist that preserve first-order queries. We use previously known properties of logical formulas and graphs, and build on them with some technical work to make them work in our context. This constitutes a part of the first steps to understand the extent to which techniques from algorithm design and computational learning theory can be adapted for watermarking.","PeriodicalId":175000,"journal":{"name":"Foundations of Software Technology and Theoretical Computer Science","volume":"36 5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114043801","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Regular Separability and Intersection Emptiness are Independent Problems","authors":"R. Thinniyam, Georg Zetzsche","doi":"10.4230/LIPIcs.FSTTCS.2019.51","DOIUrl":"https://doi.org/10.4230/LIPIcs.FSTTCS.2019.51","url":null,"abstract":"The problem of emph{regular separability} asks, given two languages $K$ and $L$, whether there exists a regular language $S$ with $Ksubseteq S$ and $Scap L=emptyset$. This problem has recently been studied for various classes of languages. All the results on regular separability obtained so far exhibited a noteworthy correspondence with the intersection emptiness problem: In eachcase, regular separability is decidable if and only if intersection emptiness is decidable. This raises the question whether under mild assumptions, regular separability can be reduced to intersection emptiness and vice-versa. \u0000We present counterexamples showing that none of the two problems can be reduced to the other. More specifically, we describe language classes $mathcal{C_1}$, $mathcal{D_1}$, $mathcal{C_2}$, $mathcal{D_2}$ such that (i)~intersection emptiness is decidable for $mathcal{C_1}$ and $mathcal{D_1}$, but regular separability is undecidable for $mathcal{C_1}$ and $mathcal{D_1}$ and (ii)~regular separability is decidable for $mathcal{C_2}$ and $mathcal{D_2}$, but intersection emptiness is undecidable for $mathcal{C_2}$ and $mathcal{D_2}$.","PeriodicalId":175000,"journal":{"name":"Foundations of Software Technology and Theoretical Computer Science","volume":"253 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132825286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Two-way Parikh Automata","authors":"E. Filiot, Shibashis Guha, Nicolas Mazzocchi","doi":"10.4230/LIPIcs.FSTTCS.2019.40","DOIUrl":"https://doi.org/10.4230/LIPIcs.FSTTCS.2019.40","url":null,"abstract":"Parikh automata extend automata with counters whose values can only be tested at the end of the computation, with respect to membership into a semi-linear set. Parikh automata have found several applications, for instance in transducer theory, as they enjoy decidable emptiness problem. In this paper, we study two-way Parikh automata. We show that emptiness becomes undecidable in the non-deterministic case. However, it is PSpace-C when the number of visits to any input position is bounded and the semi-linear set is given as an existential Presburger formula. We also give tight complexity bounds for the inclusion, equivalence and universality problems. Finally, we characterise precisely the complexity of those problems when the semi-linear constraint is given by an arbitrary Presburger formula.","PeriodicalId":175000,"journal":{"name":"Foundations of Software Technology and Theoretical Computer Science","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123232549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Minimisation of Event Structures","authors":"Paolo Baldan, Alessandra Raffaetà","doi":"10.4230/LIPIcs.FSTTCS.2019.30","DOIUrl":"https://doi.org/10.4230/LIPIcs.FSTTCS.2019.30","url":null,"abstract":"Event structures are fundamental models in concurrency theory, providing a representation of events in computation and of their relations, notably concurrency, conflict and causality. In this paper we present a theory of minimisation for event structures. Working in a class of event structures that generalises many stable event structure models in the literature (e.g., prime, asymmetric, flow and bundle event structures), we study a notion of behaviour-preserving quotient, referred to as a folding, taking (hereditary) history preserving bisimilarity as a reference behavioural equivalence. We show that for any event structure a folding producing a uniquely determined minimal quotient always exists. We observe that each event structure can be seen as the folding of a prime event structure, and that all foldings between general event structures arise from foldings of (suitably defined) corresponding prime event structures. This gives a special relevance to foldings in the class of prime event structures, which are studied in detail. We identify folding conditions for prime and asymmetric event structures, and show that also prime event structures always admit a unique minimal quotient (while this is not the case for various other event structure models).","PeriodicalId":175000,"journal":{"name":"Foundations of Software Technology and Theoretical Computer Science","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115143654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Distance Between Mutually Reachable Petri Net Configurations","authors":"Jérôme Leroux","doi":"10.4230/LIPIcs.FSTTCS.2019.47","DOIUrl":"https://doi.org/10.4230/LIPIcs.FSTTCS.2019.47","url":null,"abstract":"Petri nets are a classical model of concurrency widely used and studied in formal verification with many applications in modeling and analyzing hardware and software, data bases, and reactive systems. The reachability problem is centralsince many other problems reduce to reachability questions. In 2015, we proved that a variant of the reachability problem, called the reversible reachability problem is exponential-space complete. Recently, this problem found several unexpected applications in particular in the theory of population protocols. In this paper we propose to revisit the reversible reachability problem in order to prove that the minimal distance in the reachability graph of two mutually reachable configurations is linear with respect to the Euclidian distance between those two configurations.","PeriodicalId":175000,"journal":{"name":"Foundations of Software Technology and Theoretical Computer Science","volume":"45 5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132498435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Giorgio Lucarelli, Benjamin Moseley, Nguyen Kim Thang, Abhinav Srivastav, D. Trystram
{"title":"Online Non-Preemptive Scheduling to Minimize Maximum Weighted Flow-Time on Related Machines","authors":"Giorgio Lucarelli, Benjamin Moseley, Nguyen Kim Thang, Abhinav Srivastav, D. Trystram","doi":"10.4230/LIPIcs.FSTTCS.2019.24","DOIUrl":"https://doi.org/10.4230/LIPIcs.FSTTCS.2019.24","url":null,"abstract":"We consider the problem of scheduling jobs to minimize the maximum weighted flow-timeon a set of related machines. When jobs can be preempted this problem is well-understood; forexample, there exists a constant competitive algorithm using speed augmentation. When jobs mustbe scheduled non-preemptively, only hardness results are known. In this paper, we present thefirst online guarantees for the non-preemptive variant. We present the first constant competitivealgorithm for minimizing the maximum weighted flow-time on related machines by relaxing theproblem and assuming that the online algorithm can reject a small fraction of the total weight ofjobs. This is essentially the best result possible given the strong lower bounds on the non-preemptiveproblem without rejection.","PeriodicalId":175000,"journal":{"name":"Foundations of Software Technology and Theoretical Computer Science","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132754611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Hyper Partial Order Logic","authors":"B. Bérard, S. Haar, L. Hélouët","doi":"10.4230/LIPIcs.FSTTCS.2018.20","DOIUrl":"https://doi.org/10.4230/LIPIcs.FSTTCS.2018.20","url":null,"abstract":"We define HyPOL, a local hyper logic for partial order models, expressing properties of sets ofruns. These properties depict shapes of causal dependencies in sets of partially ordered executions,with similarity relations defined as isomorphisms of past observations. Unsurprisingly, sincecomparison of projections are included, satisfiability of this logic is undecidable. We then addressmodel checking of HyPOL and show that, already for safe Petri nets, the problem is undecidable.Fortunately, sensible restrictions of observations and nets allow us to bring back model checking ofHyPOL to a decidable problem, namely model checking of MSO on graphs of bounded treewidth.","PeriodicalId":175000,"journal":{"name":"Foundations of Software Technology and Theoretical Computer Science","volume":"168 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116447998","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A Hypersequent Calculus with Clusters for Tense Logic over Ordinals","authors":"David Baelde, Anthony Lick, S. Schmitz","doi":"10.4230/LIPIcs.FSTTCS.2018.15","DOIUrl":"https://doi.org/10.4230/LIPIcs.FSTTCS.2018.15","url":null,"abstract":"Prior's tense logic forms the core of linear temporal logic, with both past-and future-looking modalities. We present a sound and complete proof system for tense logic over ordinals. Technically , this is a hypersequent system, enriched with an ordering, clusters, and annotations. The system is designed with proof search algorithms in mind, and yields an optimal coNP complexity for the validity problem. It entails a small model property for tense logic over ordinals: every satisfiable formula has a model of order type at most ω². It also allows to answer the validity problem for ordinals below or exactly equal to a given one.","PeriodicalId":175000,"journal":{"name":"Foundations of Software Technology and Theoretical Computer Science","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131107710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}