CCS expressions finite state processes, and three problems of equivalence
Information and Computation
A logspace algorithm for tree canonization (extended abstract)
STOC '92 Proceedings of the twenty-fourth annual ACM symposium on Theory of computing
A polynomial algorithm for deciding bisimilarity of normed context-free processes
Theoretical Computer Science
Counting and random generation of strings in regular languages
Proceedings of the sixth annual ACM-SIAM symposium on Discrete algorithms
Journal of the ACM (JACM)
Efficiency of Fast Parallel Pattern Searching in Highly Compressed Texts
MFCS '99 Proceedings of the 24th International Symposium on Mathematical Foundations of Computer Science
Efficient Algorithms for Lempel-Zip Encoding (Extended Abstract)
SWAT '96 Proceedings of the 5th Scandinavian Workshop on Algorithm Theory
Complexity of Language Recognition Problems for Compressed Words
Jewels are Forever, Contributions on Theoretical Computer Science in Honor of Arto Salomaa
The Definability of Equational Graphs in Monadic Second-Order Logic
ICALP '89 Proceedings of the 16th International Colloquium on Automata, Languages and Programming
An Improved Pattern Matching Algorithm for Strings in Terms of Straight-Line Programs
CPM '97 Proceedings of the 8th Annual Symposium on Combinatorial Pattern Matching
Testing Equivalence of Morphisms on Context-Free Languages
ESA '94 Proceedings of the Second Annual European Symposium on Algorithms
Word problems requiring exponential time(Preliminary Report)
STOC '73 Proceedings of the fifth annual ACM symposium on Theory of computing
Completeness results for graph isomorphism
Journal of Computer and System Sciences
An undecidable property of context-free linear orders
Information Processing Letters
Isomorphism of regular trees and words
ICALP'11 Proceedings of the 38th international conference on Automata, languages and programming - Volume Part II
Faster fully compressed pattern matching by recompression
ICALP'12 Proceedings of the 39th international colloquium conference on Automata, Languages, and Programming - Volume Part I
Deciding whether the frontier of a regular tree is scattered
Fundamenta Informaticae
Processing compressed texts: a tractability border
CPM'07 Proceedings of the 18th annual conference on Combinatorial Pattern Matching
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The computational complexity of the isomorphism problem for regular trees, regular linear orders, and regular words is analyzed. A tree is regular if it is isomorphic to the prefix order on a regular language. In case regular languages are represented by NFAs (DFAs), the isomorphism problem for regular trees turns out to be EXPTIME-complete (resp. P-complete). In case the input automata are acyclic NFAs (acyclic DFAs), the corresponding trees are (succinctly represented) finite trees, and the isomorphism problem turns out to be PSPACE-complete (resp. P-complete). A linear order is regular if it is isomorphic to the lexicographic order on a regular language. A polynomial time algorithm for the isomorphism problem for regular linear orders (and even regular words, which generalize the latter) given by DFAs is presented. This solves an open problem by Esik and Bloom. Similar techniques can be used to show that one can check in polynomial time whether a given regular linear order has a non-trivial automorphism. This improves a recent decidability result of Kuske.