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Recursive queries and context-free graph grammars

Bruno Courcelle
1991 Theoretical Computer Science  
., Recursive queries and context-free graph grammars, Theoretical Computer Science 78 (1991) 217-244.  ...  The semantics of a recursive query in the context of a relational database can be formalized in terms of a context-free graph grammar associated with it.  ...  Recursive queries and context-free grammars 239 of "good" formulas). Let [f be the subset of !  ... 
doi:10.1016/0304-3975(51)90009-6 fatcat:teimdywbwfhfzf2n4mpcmrw2gy

Querying for Paths in Graphs using Context-Free Path Queries [article]

Jelle Hellings
2016 arXiv   pre-print
Navigational queries for graph-structured data, such as the regular path queries and the context-free path queries, are usually evaluated to a relation of node-pairs (m, n) such that there is a path from  ...  While focusing on context-free path queries, we provide a formal framework for evaluating queries on graphs using both path-based query semantics.  ...  Let C = (N, Σ, P) be a context-free grammar and let G = (Q, Σ, δ) be a graph.  ... 
arXiv:1502.02242v2 fatcat:ndt2ybgf7jhvvpb3jksrhnpw4a

Cumulative subject index volumes 40–43

1979 Information and Control  
, graph property measurements, and closure proper- ties, 42, 305 graph and subgraph isomorphism, and graph structure recognition, 42, 330 families, generated by context free graph grammars, 42,  ...  conditional, generative capacity, 43, 178 graph, context free: families of graphs generated by, 42, 72 inside-out, Szilard languages of, 40, 319 linear context free, average stack size of derivation  ... 
doi:10.1016/s0019-9958(79)90069-x fatcat:prorkxke6ncuzeb52kxef5whba

GRAMMARS AND AUTOMATA TO OPTIMIZE CHAIN LOGIC QUERIES

SERGIO GRECO, DOMENICO SACCÀ, CARLO ZANIOLO
1999 International Journal of Foundations of Computer Science  
The method, called pushdown method, is based on the fact that each chain query can be associated with a context-free language, and that a pushdown automaton recognizing this language can be emulated by  ...  The critical problem of finding efficient implementations for recursive queries with bound arguments offers many open challenges of practical and theoretical import.  ...  The Pushdown Method Our method, called pushdown method is based on the analogy of chain queries and context-free grammars [32] .  ... 
doi:10.1142/s0129054199000253 fatcat:bea37siforcuzk66cnb5notoxq

Page 436 of Mathematical Reviews Vol. , Issue 92a [page]

1992 Mathematical Reviews  
Summary: “The semantics of a recursive query in the context of a relational database can be formalized in terms of a context- free graph grammar associated with it.  ...  graph grammars.  ... 

Page 3353 of Mathematical Reviews Vol. , Issue 2001E [page]

2001 Mathematical Reviews  
Summary: “Context-free hypergraph grammars allow the defini- tion of sets of hypergraphs in a recursive way.  ...  With respect to their graph-generating power, S-HH grammars and so-called remote-free C-hNCE grammars characterize confluent node rewriting in graphs, which in turn is more powerful than hyperedge rewriting  ... 

On the computational power of context-free PC grammar systems

Niculae Mandache
2000 Theoretical Computer Science  
It is shown that non-returning parallel communicating grammar systems with -free contextfree components can generate any recursively enumerable language.  ...  Since it was proven that such systems can be simulated by returning PC grammar systems with context-free components, the result extends to those.  ...  We settle here the question by proving that for any recursively enumerable language L there is a non-returning PC grammar systems with -free context-free components which generates L.  ... 
doi:10.1016/s0304-3975(98)00159-5 fatcat:czxsxipgljeoxjoay6nsmow42a

Cumulative subject index volumes 56–59

1983 Information and Control  
and inclusion, implication problem for, 56, 154 Determinism in dynamic logic, 57, 48 Deterministic context-free dynamic logic regular dynamic logic not interpretable in, 59, 94 Deterministic context-free  ...  and always), in loop invariants: in program verification, 57, 165 and space, deterministic context free language recognition in, 56, 34 Translation lemma and corollaries, and decidability of equivalence  ... 
doi:10.1016/s0019-9958(83)80037-0 fatcat:dtwnjwpfbndyfc26jagdqcnmwa

An Efficient Algorithm for Solving the Dyck-CFL Reachability Problem on Trees [chapter]

Hao Yuan, Patrick Eugster
2009 Lecture Notes in Computer Science  
The context-free language (CFL) reachability problem is well known and studied in computer science, as a fundamental problem underlying many important static analyses such as points-to-analysis.  ...  Popular solutions resorting to a graph traversal exhibit a time complexity of O(k 3 n 3 ) for a grammar of size k.  ...  Possible future work can be considering dynamic graph updates, i.e., graph nodes and edges are added/deleted dynamically and online CFL reachability queries need to be answered efficiently.  ... 
doi:10.1007/978-3-642-00590-9_13 fatcat:24pa77ycrndr7pikss37ruwqtm

Efficient techniques for parsing with tree automata

Jonas Groschwitz, Alexander Koller, Mark Johnson
2016 Proceedings of the 54th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)  
We present techniques that speed up tree-automata-based parsing, to the point that it becomes practically feasible on realistic data when applied to context-free, TAG, and graph parsing.  ...  For graph parsing, we obtain the best runtimes in the literature.  ...  We are grateful to Johannes Gontrum for an early implementation of Alg. 4, and to Christoph Teichmann for many fruitful discussions. This work was supported by the DFG grant KO 2916/2-1.  ... 
doi:10.18653/v1/p16-1192 dblp:conf/acl/GroschwitzKJ16 fatcat:5rxnu65ztrbxhp5rfuoui4x3tm

Context-Free Path Queries on RDF Graphs [article]

Xiaowang Zhang, Zhiyong Feng, Xin Wang, Guozheng Rao, Wenrui Wu
2016 arXiv   pre-print
To overcome this limitation, in this paper, we present cfSPARQL, an extension of SPARQL query language equipped with context-free grammars.  ...  Navigational graph queries are an important class of queries that canextract implicit binary relations over the nodes of input graphs.  ...  Acknowledgments The authors thank Jelle Hellings and Guohui Xiao for their helpful and constructive comments.  ... 
arXiv:1506.00743v3 fatcat:jor6wnudqjcpfom5zitpcppbey

Search and Result Presentation in Scientific Workflow Repositories [article]

Susan B. Davidson and Xiaocheng Huang and Julia Stoyanovich and Xiaojie Yuan
2013 arXiv   pre-print
Since keyword search does not use the graph structure of a workflow, we develop a model of workflows using context-free bag grammars.  ...  We then give efficient polynomial-time algorithms that, given a workflow and a keyword query, determine whether some execution of the workflow matches the query.  ...  ACKNOWLEDGEMENTS We thank Tova Milo for extensive discussions and feedback on this draft.  ... 
arXiv:1305.4195v2 fatcat:kuky4gaglvd4lp6q3fkzi6ndwy

One Algorithm to Evaluate Them All: Unified Linear Algebra Based Approach to Evaluate Both Regular and Context-Free Path Queries [article]

Ekaterina Shemetova, Rustam Azimov, Egor Orachev, Ilya Epelbaum, Semyon Grigorev
2021 arXiv   pre-print
Our evaluation shows that our algorithm is a good candidate to be the universal algorithm for both regular and context-free path querying.  ...  The Kronecker product-based algorithm for context-free path querying (CFPQ) was proposed by Orachev et al. (2020).  ...  Acknowledgements We are grateful to Ekaterina Verbitskaia for careful reading and pointing out some mistakes.  ... 
arXiv:2103.14688v1 fatcat:fy73vloj5zcmjbbwis37rbexte

Rational index of bounded-oscillation languages [article]

Ekaterina Shemetova, Alexander Okhotin, Semyon Grigorev
2020 arXiv   pre-print
It is known that the context-free language (CFL-)reachability problem and Datalog query evaluation for context-free languages (queries) with the polynomial rational index is in NC, while these problems  ...  The rational index of a context-free language L is a function f(n), such that for each regular language R recognized by an automaton with n states, the intersection of L and R is either empty or contains  ...  context-free grammar representation of this query and the edge-labeled graph G.  ... 
arXiv:2012.03567v1 fatcat:6og66bybfjgadec44uulheeowu

Bounds on the propagation of selection into logic programs

Catriel Beeri, Paris Kanellakis, Francois Bancilhon, Raghu Ramakrishnan
1990 Journal of computer and system sciences (Print)  
We further clarify the analogy between chain programs and context-free languages from the point of view of program equivalence, first-order expressibility over finite structures, and selection propagation  ...  We associate a context free language L(H) with every chain program H. We show that, given H, propagating a selection involving some constant is possible iff L(H) is regular and therefore undecidable.  ...  ACKNOWLEDGMENTS We thank Stavros Cosmadakis, Ron Fagin, Phokion Kolaitis, and Moshe Vardi for their many helpful comments.  ... 
doi:10.1016/0022-0000(90)90035-j fatcat:5mkro4bjhncxleun6zk5vtmrrm
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