Projects

 
Project Title Tree Automata & Tree Algorithms
Project Members Loek Cleophas, dr.ir. Kees Hemerik, dr.ir. Gerard Zwaan and prof. dr. Bruce W. Watson
Abstract
In this project, we aim to develop taxonomies and toolkits of tree algorithms. In particular, three types of tree algorithms seem interesting:
  • algorithms for tree pattern matching
  • algorithms for acceptance of trees
  • algorithms for parsing trees
The concept of finite tree automata plays a central role here. Such automata form a generalization of finite automata on strings. Many algorithms for the above problems use some form of tree automata.

Although a lot of theory and practical experience for the field is available, a coherently structured classification is lacking. Parts of the theory have been around for a long time, but even though the theory might be old, the applications of tree automata are not outdated at all: algorithms of the kind mentioned above are used in applications such diverse as code generation and optimization, XML document processing, term rewriting, type inference, genetics (DNA/RNA pattern matching) and cryptography.