Explicit representation of terms defined by counter examples
Journal of Automated Reasoning
Equational formulae with membership constraints
Information and Computation
Undecidable properties of deterministic top-down tree transducers
Theoretical Computer Science
Handbook of formal languages, vol. 3
Patterns in Words versus Patterns in Trees: A Brief Survey and New Results
PSI '99 Proceedings of the Third International Andrei Ershov Memorial Conference on Perspectives of System Informatics
Regular expression pattern matching for XML
Journal of Functional Programming
Regular expression types for XML
ACM Transactions on Programming Languages and Systems (TOPLAS)
Taxonomy of XML schema languages using formal language theory
ACM Transactions on Internet Technology (TOIT)
Tree acceptors and some of their applications
Journal of Computer and System Sciences
Classes of tree homomorphisms with decidable preservation of regularity
FOSSACS'08/ETAPS'08 Proceedings of the Theory and practice of software, 11th international conference on Foundations of software science and computational structures
The HOM Problem is EXPTIME-Complete
LICS '12 Proceedings of the 2012 27th Annual IEEE/ACM Symposium on Logic in Computer Science
Journal of the ACM (JACM)
Excessively duplicating patterns represent non-regular languages
Information Processing Letters
Hi-index | 0.00 |
Finite-state tree automata are a well-studied formalism for representing term languages. This paper studies the problem of determining the regularity of the set of instances of a finite set of terms with variables, where each variable is restricted to instantiations of a regular set given by a tree automaton. The problem was recently proved decidable, but with an unknown complexity. Here, the exact complexity of the problem is determined by proving EXPTIME-completeness. The main contribution is a new, exponential time algorithm that performs various exponential transformations on the involved terms and tree automata and decides regularity by analyzing formulas over inequation and height predicates.