DLT
2010
14 years 27 days ago
2010
It is known that the languages definable by formulae of the logics FO2[<,S], 2[<,S], LTL[F,P,X,Y] are exactly the variety DAD. Automata for this class are not known, nor is i...
LICS
2008
IEEE
14 years 5 months ago
2008
IEEE
— 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,...