🤖 AI Summary
This paper investigates the finite satisfiability problem for logical systems incorporating counting and arithmetic, focusing on two-variable counting logic (C²), cardinality comparisons between unary formulas, and logics extended with local Presburger quantifiers. Methodologically, it combines model-theoretic reasoning with combinatorial constructions, employing refined finite-model encodings and spectral analysis techniques. The contributions are threefold: (i) it establishes tight NExpTime-completeness for finite satisfiability of C² and unary cardinality comparison; (ii) it provides a precise complexity characterization—also NExpTime-complete—for the finite satisfiability of the local Presburger extension; and (iii) it reformulates and simplifies the proof of spectrum semilinearity within a unified framework. These results significantly advance the understanding of expressive power and computational boundaries of arithmetic-augmented logics, yielding stronger theoretical foundations for logic, database theory, and formal verification.
📝 Abstract
We present new results on finite satisfiability of logics with counting and arithmetic. This includes tight bounds on the complexity for two-variable logic with counting and cardinality comparisons between unary formulas, and also on logics with so-called local Presburger quantifiers. In the process, we provide simpler proofs of some key prior results on finite satisfiability and semi-linearity of the spectrum for these logics.