An Efficient Finite Tree Automata Library

TL;DR

This paper introduces an efficient and flexible finite tree automata library designed to support formal verification techniques that use tree automata to represent infinite state spaces, demonstrating competitive performance.

Contribution

The paper presents a new library implementation for finite tree automata, including algorithms and data structures, with experimental validation showing its effectiveness and advantages over existing libraries.

Findings

Library competes effectively with existing tools

In certain cases, library outperforms competitors

Supports standard language operations efficiently

Abstract

Numerous computer systems use dynamic control and data structures of unbounded size. These data structures have often the character of trees or they can be encoded as trees with some additional pointers. This is exploited by some currently intensively studied techniques of formal verification that represent an infinite number of states using a finite tree automaton. However, currently there is no tree automata library implementation that would provide an efficient and flexible support for such methods. Thus the aim of this Master's Thesis is to provide such a library. The present paper first describes the theoretical background of finite tree automata and regular tree languages. Then it surveys the current implementations of tree automata libraries and studies various verification techniques, outlining requirements for the library. Representation of a finite tree automaton and algorithms that perform standard language operations on this representation are proposed in the next part, which is followed by description of library implementation. Through a series of experiments it is shown that the library can compete with other available tree automata libraries, in certain areas being even significantly superior to them.