Relational queries computable in polynomial time
Information and Control
Languages that capture complexity classes
SIAM Journal on Computing
Hereditarily-finite sets, data bases and polynomial-time computability
Informatika '91 Selected papers of the 5th Soviet-French symposium on Theoretical computer science, methods and tools for compilation, and program development
Query languages for hierarchic databases
Information and Computation
The expressiveness of a family of finite set languages
Theoretical Computer Science
A query language and optimization techniques for unstructured data
SIGMOD '96 Proceedings of the 1996 ACM SIGMOD international conference on Management of data
&Dgr;-languages for sets and LOGSPACE computable graph transformers
NSL '94 Proceedings of the first workshop on Non-standard logics and logical aspects of computer science
Linear ordering on graphs, anti-founded sets and polynomial time computability
Theoretical Computer Science
Foundations of Databases: The Logical Level
Foundations of Databases: The Logical Level
Computers and Intractability: A Guide to the Theory of NP-Completeness
Computers and Intractability: A Guide to the Theory of NP-Completeness
A new approach to database logic
PODS '84 Proceedings of the 3rd ACM SIGACT-SIGMOD symposium on Principles of database systems
The Choice of Programming Primitives for SETL-Like Programming Languages
ESOP '86 Proceedings of the European Symposium on Programming
Queries and Computation on the Web
ICDT '97 Proceedings of the 6th International Conference on Database Theory
ICDT '97 Proceedings of the 6th International Conference on Database Theory
A Bounded Set Theory with Anti-Foundation Axiom and Inductive Definability
CSL '94 Selected Papers from the 8th International Workshop on Computer Science Logic
Is SETL a Suitable Language for Parallel Programming - A Theoretical Approach
CSL '87 Proceedings of the 1st Workshop on Computer Science Logic
Bounded Hyperset Theory and Web-like Data Bases
KGC '97 Proceedings of the 5th Kurt Gödel Colloquium on Computational Logic and Proof Theory
Bounded Set Theory and Polynominal Computability
FCT '87 Proceedings of the International Conference on Fundamentals of Computation Theory
The complexity of relational query languages (Extended Abstract)
STOC '82 Proceedings of the fourteenth annual ACM symposium on Theory of computing
Algebras of feasible functions
SFCS '83 Proceedings of the 24th Annual Symposium on Foundations of Computer Science
Using Agents for Concurrent Querying of Web-Like Databases via a Hyper-Set-Theoretic Approach
PSI '02 Revised Papers from the 4th International Andrei Ershov Memorial Conference on Perspectives of System Informatics: Akademgorodok, Novosibirsk, Russia
| Hi-index | 0.00 |
Two versions of a set theoretic Δ-language are considered as theoretical prototypes for "nested" data base query language where data base states and queries are represented, respectively, as hereditarily-finite (HF) sets and set theoretic operations. It is shown that these versions correspond exactly to (N/D) LOGSPACE computability over HF, respectively. Such languages over sets, capturing also PTIME, were introduced in previous works, however, descriptions of LOGSPACE over HF [A. Lisitsa and V. Sazonov, TCS (175) 1 (1997) pp. 183-222] were not completely satisfactory. Here we overcome the drawbacks of the previous approaches due to some new partial result on definability of a linear ordering over finite extensional acyclic graphs and present a unified and simplified approach.