Piecewise Testable Tree Languages

— This paper presents a decidable characterization of tree languages that can be defined by a boolean combination of Σ1 formulas. This is a tree extension of the Simon theorem, which says that a string language can be defined by a boolean combination of Σ1 formulas if and only if its syntactic monoid is J-trivial.

• Type: Conference
• Year: 2008
• Where: LICS
• Authors: Mikolaj Bojanczyk, Luc Segoufin, Howard Straubing
• Keywords: Boolean Combination, Computer Science, Decidable Characterization, LICS 2008, Σ1 Formulas