2017 32nd Annual ACM/IEEE Symposium on Logic in Computer Science (LICS)最新文献_第4页

The homomorphism problem for regular graph patterns 正则图模式的同态问题

2017 32nd Annual ACM/IEEE Symposium on Logic in Computer Science (LICS) Pub Date : 2017-06-20 DOI: 10.1109/LICS.2017.8005106

M. Romero, P. Barceló, Moshe Y. Vardi

{"title":"The homomorphism problem for regular graph patterns","authors":"M. Romero, P. Barceló, Moshe Y. Vardi","doi":"10.1109/LICS.2017.8005106","DOIUrl":"https://doi.org/10.1109/LICS.2017.8005106","url":null,"abstract":"The evaluation of conjunctive regular path queries - which form the navigational core of the query languages for graph databases - raises challenges in the context of the homomorphism problem that are not fully addressed by existing techniques. We start a systematic investigation of such challenges using a notion of homomorphism for regular graph patterns (RGPs). We observe that the RGP homomorphism problem cannot be reduced to known instances of the homomorphism problem, and new techniques need to be developed for its study. We first show that the non-uniform version of the problem is computationally harder than for the usual homomorphism problem. By establishing a connection between both problems, in turn, we postulate a dichotomy conjecture, analogous to the algebraic dichotomy conjecture held in CSP. We also look at which structural restrictions on left-hand side instances of the RGP homomorphism problem ensure efficiency. We study restrictions based on the notion of bounded treewidth modulo equivalence, which characterizes tractability for the usual homomorphism notion. We propose two such notions, based on different interpretations of RGP equivalence, and show that they both ensure the efficiency of the RGP homomorphism problem.","PeriodicalId":313950,"journal":{"name":"2017 32nd Annual ACM/IEEE Symposium on Logic in Computer Science (LICS)","volume":"69 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130141297","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}

引用次数: 9

Generalised species of rigid resource terms 刚性资源项的广义种

2017 32nd Annual ACM/IEEE Symposium on Logic in Computer Science (LICS) Pub Date : 2017-06-20 DOI: 10.1109/LICS.2017.8005093

Takeshi Tsukada, Kazuyuki Asada, C. Ong

引用次数: 24

Large scale geometries of infinite strings 无限弦的大尺度几何

2017 32nd Annual ACM/IEEE Symposium on Logic in Computer Science (LICS) Pub Date : 2017-06-20 DOI: 10.1109/LICS.2017.8005078

B. Khoussainov, Toru Takisaka

{"title":"Large scale geometries of infinite strings","authors":"B. Khoussainov, Toru Takisaka","doi":"10.1109/LICS.2017.8005078","DOIUrl":"https://doi.org/10.1109/LICS.2017.8005078","url":null,"abstract":"We introduce geometric consideration into the theory of formal languages. We aim to shed light on our understanding of global patterns that occur on infinite strings. We utilise methods of geometric group theory. Our emphasis is on large scale geometries. Two infinite strings have the same large scale geometry if there are colour preserving bi-Lipschitz maps with distortions between the strings. Call these maps quasi-isometries. Introduction of large scale geometries poses several questions. The first question asks to study the partial order induced by quasi-isometries. This partial order compares large scale geometries; as such it presents an algebraic tool for classification of global patterns. We prove there is a greatest large scale geometry and infinitely many minimal large scale geometries. The second question is related to understanding the quasi-isometric maps on various classes of strings. The third question investigates the sets of large scale geometries of strings accepted by computational models, e.g. Büchi automata. We provide an algorithm that describes large scale geometries of strings accepted by Büchi automata. This links large scale geometries with automata theory. The fourth question studies the complexity of the quasi-isometry problem. We show the problem is Σ30-complete thus providing a bridge with computability theory. Finally, the fifth question asks to build algebraic structures that are invariants of large scale geometries. We invoke asymptotic cones, a key concept in geometric group theory, defined via model-theoretic notion of ultra-product. Partly, we study asymptotic cones of algorithmically random strings thus connecting the topic with algorithmic randomness.","PeriodicalId":313950,"journal":{"name":"2017 32nd Annual ACM/IEEE Symposium on Logic in Computer Science (LICS)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130775498","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}

引用次数: 3

Common knowledge and multi-scale locality analysis in Cayley structures Cayley结构的常识与多尺度局域分析

2017 32nd Annual ACM/IEEE Symposium on Logic in Computer Science (LICS) Pub Date : 2017-06-20 DOI: 10.1109/LICS.2017.8005072

Felix Canavoi, M. Otto

引用次数: 4

Herbrand property, finite quasi-Herbrand models, and a Chandra-Merlin theorem for quantified conjunctive queries Herbrand性质，有限拟Herbrand模型，以及一个量化合取查询的Chandra-Merlin定理

2017 32nd Annual ACM/IEEE Symposium on Logic in Computer Science (LICS) Pub Date : 2017-06-20 DOI: 10.1109/LICS.2017.8005073

S. Bova, F. Mogavero

引用次数: 5

Uniform, integral and efficient proofs for the determinant identities 行列式恒等式的统一、积分和有效证明

2017 32nd Annual ACM/IEEE Symposium on Logic in Computer Science (LICS) Pub Date : 2017-06-20 DOI: 10.1109/LICS.2017.8005099

Iddo Tzameret, S. Cook

引用次数: 5

A cartesian-closed category for higher-order model checking 用于高阶模型检验的笛卡尔闭范畴

2017 32nd Annual ACM/IEEE Symposium on Logic in Computer Science (LICS) Pub Date : 2017-06-20 DOI: 10.1109/LICS.2017.8005120

M. Hofmann, J. Ledent

引用次数: 9

Foundations of information integration under bag semantics 包语义下信息集成的基础

2017 32nd Annual ACM/IEEE Symposium on Logic in Computer Science (LICS) Pub Date : 2017-06-20 DOI: 10.1109/LICS.2017.8005104

André Hernich, Phokion G. Kolaitis

{"title":"Foundations of information integration under bag semantics","authors":"André Hernich, Phokion G. Kolaitis","doi":"10.1109/LICS.2017.8005104","DOIUrl":"https://doi.org/10.1109/LICS.2017.8005104","url":null,"abstract":"During the past several decades, the database theory community has successfully investigated several different facets of the principles of database systems, including the development of various data models, the systematic exploration of the expressive power of database query languages, and, more recently, the study of the foundations of information integration via schema mappings. For the most part, all these investigations have been carried out under set semantics, that is, both the database relations and the answers to database queries are sets. In contrast, SQL deploys bag (multiset) semantics and, as a result, theory and practice diverge at this crucial point. Our main goal in this paper is to embark on the development of the foundations of information integration under bag semantics, thus taking the first step towards bridging the gap between theory and practice in this area. Our first contribution is conceptual, namely, we give rigorous bag semantics to GLAV mappings and to the certain answers of conjunctive queries in the context of data exchange and data integration. In fact, we introduce and explore two different versions of bag semantics that, intuitively, correspond to the maximum-based union of bags and to the sum-based union of bags. After this, we establish a number of technical results, including results about the computational complexity of the certain answers of conjunctive queries under bag semantics and about the existence and computation of universal solutions under these two versions of bag semantics. Our results reveal that the adoption of more realistic semantics comes at a price, namely, algorithmic problems in data exchange and data integration that were tractable under set semantics become intractable under bag semantics.","PeriodicalId":313950,"journal":{"name":"2017 32nd Annual ACM/IEEE Symposium on Logic in Computer Science (LICS)","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114565736","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}

引用次数: 15

Partial derivatives on graphs for Kleene allegories Kleene寓言图上的偏导数

2017 32nd Annual ACM/IEEE Symposium on Logic in Computer Science (LICS) Pub Date : 2017-06-20 DOI: 10.1109/LICS.2017.8005132

Yoshiki Nakamura

引用次数: 13

Symbolic execution and probabilistic reasoning 符号执行和概率推理

2017 32nd Annual ACM/IEEE Symposium on Logic in Computer Science (LICS) Pub Date : 2017-06-20 DOI: 10.1109/LICS.2017.8005062

C. Pasareanu

引用次数: 0