Equality and Disequality Constraints on Direct Subterms in Tree Automata
STACS '92 Proceedings of the 9th Annual Symposium on Theoretical Aspects of Computer Science
Testing Equivalence of Morphisms on Context-Free Languages
ESA '94 Proceedings of the Second Annual European Symposium on Algorithms
The complexity of tree automata and XPath on grammar-compressed trees
Theoretical Computer Science - Implementation and application of automata
Path queries on compressed XML
VLDB '03 Proceedings of the 29th international conference on Very large data bases - Volume 29
Efficient memory representation of XML document trees
Information Systems
Context Matching for Compressed Terms
LICS '08 Proceedings of the 2008 23rd Annual IEEE Symposium on Logic in Computer Science
Tree automata with memory, visibility and structural constraints
FOSSACS'07 Proceedings of the 10th international conference on Foundations of software science and computational structures
Bounded second-order unification is NP-complete
RTA'06 Proceedings of the 17th international conference on Term Rewriting and Applications
Unification with Singleton Tree Grammars
RTA '09 Proceedings of the 20th International Conference on Rewriting Techniques and Applications
Unification and matching on compressed terms
ACM Transactions on Computational Logic (TOCL)
Congruence closure of compressed terms in polynomial time
FroCoS'11 Proceedings of the 8th international conference on Frontiers of combining systems
Parameter reduction and automata evaluation for grammar-compressed trees
Journal of Computer and System Sciences
| Hi-index | 0.00 |
Trees can be conveniently compressed with linear straight-line context-free tree grammars. Such grammars generalize straight-line context-free string grammars which are widely used in the development of algorithms that execute directly on compressed structures (without prior decompression). It is shown that every linear straight-line context-free tree grammar can be transformed in polynomial time into a monadic (and linear) one. A tree grammar is monadic if each nonterminal uses at most one context parameter. Based on this result, a polynomial time algorithm is presented for testing whether a given nondeterministic tree automaton with sibling constraints accepts a tree given by a linear straight-line context-free tree grammar. It is shown that if tree grammars are nondeterministic or non-linear, then reducing their numbers of parameters cannot be done without an exponential blow-up in grammar size.