Decision problems for patterns
Journal of Computer and System Sciences
A note on the equivalence problem of E-patterns
Information Processing Letters
On the equivalence problem for E-pattern languages
Theoretical Computer Science
Reversal-Bounded Multicounter Machines and Their Decision Problems
Journal of the ACM (JACM)
The expressibility of languages and relations by word equations
Journal of the ACM (JACM)
Handbook of Formal Languages
Polynomial Time Inference of Extended Regular Pattern Languages
Proceedings of RIMS Symposium on Software Science and Engineering
The Relation of Two Patterns with Comparable Languages
STACS '88 Proceedings of the 5th Annual Symposium on Theoretical Aspects of Computer Science
A non-learnable class of E-pattern languages
Theoretical Computer Science - Algorithmic learning theory(ALT 2002)
Discontinuities in pattern inference
Theoretical Computer Science
Developments from enquiries into the learnability of the pattern languages from positive data
Theoretical Computer Science
Journal of Automata, Languages and Combinatorics
Compute inclusion depth of a pattern
COLT'05 Proceedings of the 18th annual conference on Learning Theory
Expressive languages for path queries over graph-structured data
Proceedings of the twenty-ninth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Existence and nonexistence of descriptive patterns
Theoretical Computer Science
Inclusion problems for patterns with a bounded number of variables
DLT'10 Proceedings of the 14th international conference on Developments in language theory
Regular patterns, regular languages and context-free languages
Information Processing Letters
Regular and context-free pattern languages over small alphabets
DLT'12 Proceedings of the 16th international conference on Developments in Language Theory
Expressive Languages for Path Queries over Graph-Structured Data
ACM Transactions on Database Systems (TODS)
Inclusion problems for patterns with a bounded number of variables
Information and Computation
Inferring descriptive generalisations of formal languages
Journal of Computer and System Sciences
Proceedings of the 32nd symposium on Principles of database systems
A note on the complexity of matching patterns with variables
Information Processing Letters
Regular and context-free pattern languages over small alphabets
Theoretical Computer Science
Hi-index | 0.00 |
We study the inclusion problem for pattern languages, which-due to Jiang et al. [T. Jiang, A. Salomaa, K. Salomaa, S. Yu, Decision problems for patterns, Journal of Computer and System Sciences 50 (1995) 53-63]-is known to be undecidable. More precisely, Jiang et al. demonstrate that there is no effective procedure deciding the inclusion for the class of all pattern languages over all alphabets. Most applications of pattern languages, however, consider classes over fixed alphabets, and therefore it is practically more relevant to ask for the existence of alphabet-specific decision procedures. Our first main result states that, for all but very particular cases, this version of the inclusion problem is also undecidable. The second main part of our paper disproves the prevalent conjecture on the inclusion of so-called similar E-pattern languages, and it explains the devastating consequences of this result for the intensive previous research on the most prominent open decision problem for pattern languages, namely the equivalence problem for general E-pattern languages.