Languages, automata, and logic
Handbook of formal languages, vol. 3
Journal of Computer and System Sciences - 30th annual ACM symposium on theory of computing
Petri Net Theory and the Modeling of Systems
Petri Net Theory and the Modeling of Systems
Introduction to Formal Language Theory
Introduction to Formal Language Theory
Logics For Context-Free Languages
CSL '94 Selected Papers from the 8th International Workshop on Computer Science Logic
Monadic Logical Definability of NP-Complete Problems
CSL '94 Selected Papers from the 8th International Workshop on Computer Science Logic
Existential Second-Order Logic over Strings
LICS '98 Proceedings of the 13th Annual IEEE Symposium on Logic in Computer Science
Note: a descriptive complexity approach to the linear hierarchy
Theoretical Computer Science
Tree acceptors and some of their applications
Journal of Computer and System Sciences
A logical characterisation of linear time on nondeterministic turing machines
STACS'99 Proceedings of the 16th annual conference on Theoretical aspects of computer science
The model checking problem for prefix classes of second-order logic: a survey
Fields of logic and computation
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In this paper, we explore the expressive power of fragments of monadic second-order logic enhanced with some generalized quantifiers of comparison of cardinality over finite word structures. The full monadic second-order fragment of the logics that we study correspond to the famous linear hierarchy, see [Y. Hachaichi, A descriptive complexity approach to the linear hierarchy, Theoretical Computer Science 304 (2003) 421-429], and their existential fragments characterize some sequential recognizers. We prove that the first-order closure of the existential fragments of these logics is strictly beyond the existential fragments.