Arbology Research Group

Our research is focussed on several areas of computer science, both classical ones and modern ones. We have quite a long research tradition in formal languages and automata theory, compiler construction (both front-end and back-end parts), and implementation of programming languages. Recently, we have focussed on arbology, a new theory of algorithms for processing tree data structures. Examples of such tree structures can be abstract syntax trees or XML documents. The main idea of the arbology is to apply principles inspired by stringology to the domain of tree data processing.


  • Abstract syntax tree processing and code generation
  • Computing regularities and repetitions in trees
  • Efficient parsing and translation methods
  • Indexing trees
  • Input-driven pushdown automata and their determinization
  • Multilanguage virtual machines
  • Processing directed acyclic graphs, 2D automata
  • Tree and pushdown automata
  • Tree pattern matching
  • XML processing




TA030010964 (Technology Agency of the Czech Republic): Tools for Automatizing the Quality Assurance in Large Business Intelligence Systems and Data Warehouses, main investigator: doc. Ing. Jan Janoušek, Ph.D., 01/2013 - 12/2016.
13-03253S (Czech Science Foundation): Text and Tree Structures Processing and Their Applications, main investigator: doc. Ing. Jan Holub, Ph.D., 02/2013 - 12/2015.

JANOUŠEK, J., MELICHAR, B., POLÁCH, R., POLIAK, M., and TRÁVNÍČEK, J.: A Full and Linear Index of a Tree for Tree Patterns. In: Descriptional Complexity of Formal Systems - 16th International Workshop, Springer, 2014, LNCS 8614, 198-209. ISSN 0302-9743.
LAHODA, J. and ŽĎÁREK, J.: Simple Tree Pattern Matching for Trees in the Prefix Bar Notation. Discrete Applied Mathematics, 2014, 163(3), 343-351. ISSN 0166-218X.
HLOPKO, M., KURŠ, J.,  VRANÝ, J., and GITTINGER, C.: On the Integration of Smalltalk and Java. Science of Computer Programming,  2013, ISSN 0167-6423. In press, DOI:10.1016/j.scico.2013.10.011.
CHRISTOU, M., CROCHEMORE, M., FLOURI, T., ILIOPOULOS, C.S., JANOUŠEK, J., MELICHAR, B., and PISSIS, S.: Computing all subtree repeats in ordered trees. Information Processing Letters, 2012, 112(24), 958-962. ISSN 0020-0190.
JANOUŠEK, J., MELICHAR, B., and POLIAK, M.: Tree compression pushdown automaton. Kybernetika, 2012, 48(3), 429-452. ISSN 0023-5954.
MELICHAR, B., JANOUŠEK, J., and FLOURI, T.: Arbology: Trees and pushdown automata. Kybernetika, 2012, 48(3), 402-428. ISSN 0023-5954.
TRÁVNÍČEK, J., JANOUŠEK, J., and MELICHAR, B.: Indexing ordered trees for (nonlinear) tree pattern matching. Computer Science and Information Systems, 2012, 9(3), 1125-1153. ISSN 1820-0214.
ŽĎÁREK, J. and MELICHAR, B.: Tree-Based 2D Indexing. International Journal of Foundations of Computer Science, 2011, 22(8), 1893-1907. ISSN 0129-0541.
FLOURI, T., JANOUŠEK, J., and MELICHAR, B.: Subtree Matching by Pushdown Automata. Computer Science and Information Systems, 2010, 7(2), 332-357. ISSN 1820-0214.
JANOUŠEK, J. and MELICHAR, B.: On regular tree languages and deterministic pushdown automata. Acta Informatica, 2009, 46(7), 533-547. ISSN 0001-5903.


Doc. Ing. Jan Janoušek, Ph.D.


Last modified: 22.1.2019, 15:30