一句话:证明带元组模/阈值/精确计数量词的 Presburger 算术可判定,并给出双指数空间与交替时间上界。
本文研究整数加法的一阶逻辑,即 Presburger 算术,并扩展以作用于变量元组的模计数、阈值计数和精确计数量词。主要结果是该逻辑的满足性问题可在双指数空间内判定。若仅允许阈值与精确计数,则给出交替双指数时间且交替次数线性有界的上界,几乎匹配 Berman 对无计数一阶逻辑的精确复杂度。方法上,先将阈值和精确计数量词多项式时间归约到经典一阶逻辑;再把元组模计数量词双指数归约到单元素模计数,并用类似 Reddy–Loveland 的量词消去分析系数与模增长,从而限制量词范围。该逻辑与 Chistikov 等 2022 的逻辑不可比。
We consider a first-order logic for the integers with addition. This logic extends classical first-order logic by modulo-counting, threshold-counting and exact-counting quantifiers, all applied to tuples of variables (here, residues are given as terms while moduli and thresholds are given explicitly). Our main result shows that satisfaction for this logic is decidable in two-fold exponential space. If only threshold- and exact-counting quantifiers are allowed, we prove an upper bound of alternating two-fold exponential time with linearly many alternations. This latter result almost matches Berman's exact complexity of first-order logic without counting quantifiers. To obtain these results, we first translate threshold- and exact-counting quantifiers into classical first-order logic in polynomial time (which already proves the second result). To handle the remaining modulo-counting quantifiers for tuples, we first reduce them in doubly exponential time to modulo-counting quantifiers for single elements. For these quantifiers, we provide a quantifier elimination procedure similar to Reddy and Loveland's procedure for first-order logic and analyse the growth of coefficients, constants, and moduli appearing in this process. The bounds obtained this way allow to restrict quantification in the original formula to integers of bounded size which then implies the first result mentioned above. Our logic is incomparable with the logic considered by Chistikov et al. in 2022. They allow more general counting operations in quantifiers, but only unary quantifiers. The move from unary to non-unary quantifiers is non-trivial, since, e.g., the non-unary version of the H\"artig quantifier results in an undecidable theory.
@article{paperbot2206,
title = {On Presburger arithmetic extended with non-unary counting quantifiers},
author = {Peter Habermehl and Dietrich Kuske},
journal = {Logical Methods in Computer Science},
volume = {Volume 19, Issue 3},
year = {2023},
doi = {10.46298/lmcs-19(3:4)2023}
}