Overall Objectives
Research Program
Application Domains
New Software and Platforms
New Results
Partnerships and Cooperations
XML PDF e-pub
PDF e-Pub

Section: New Results

An Efficient Translation from a modal μ-Calculus with Converse to Tree Automata

In [16], we presented a direct translation from a sub-logic of μ-calculus to non-deterministic binary automata of finite trees. The logic is an alternation-free modal μ-calculus, restricted to finite trees and where formulae are cycle-free. This logic is expressive enough to encode significant fragments of query languages (such as Regular XPath). The size of the generated automaton (the number of transitions) is bounded by 2n where n is the size of a Fischer-Ladner closure of the formula. This is an improvement over previous translations in 2n2. We have implemented our translation. In practice, our prototype effectively decides static analysis problems that were beyond reach, such as the XPath containment problem with DTDs of significant size.