Аннотация:
Let $\mathsf{QPL}^{\mathrm{e}}$ expand the quantifier-free “polynomial” probability logic of [4] (R. Fagin et al., 1990) by adding quantifiers over arbitrary events; it can be viewed as a one-sorted elementary language for reasoning about probability spaces. We prove that the $\Sigma_2$-fragment of the $\mathsf{QPL}^{\mathrm{e}}$-theory of finite spaces is hereditarily undecidable. By earlier observations, this implies that $\Pi_2$ is the maximal decidable prefix fragment of $\mathsf{QPL}^{\mathrm{e}}$. Moreover, we obtain similar results for two natural one-sorted logics of probability that emerge from [1]
(M. Abadi and J. Y. Halpern, 1994).
Bibliography: 16 titles.
Ключевые слова:
probability logic, decidability, prefix fragments, elementary theories.
Поступило в редакцию: 23.09.2024 Исправленный вариант: 03.12.2024
Образец цитирования:
S. O. Speranski, “On the decision problem for quantified probability logics”, Изв. РАН. Сер. матем., 89:3 (2025), 193–211; Izv. Math., 89:3 (2025), 609–627