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Sharpening complexity results in quantified probability logic
Logic Journal of the IGPL. 2025. Vol. 33. No. 3. Article jzae114.
We shall be concerned with two natural expansions of the quantifier-free ‘polynomial’ probability logic of [Fagin et al. 1990]. One of these, denoted by QPL-e, is obtained by adding quantifiers over arbitrary events, and the other, denoted by p-QPL-e, uses quantifiers over propositional formulas — or equivalently, over events expressible by such formulas. The earlier proofs of the complexity lower bound results for QPL-e and p-QPL-e relied heavily on multiplication, and therefore on the polynomiality of the basic parts. We shall obtain the same lower bounds for natural fragments of QPL-e and p-QPL-e in which only linear combinations of a very special form are allowed. Also, it will be studied what happens if we add quantifiers over reals.
Kuznetsov S., Pshenitsyn T., Speranski S. O., Journal of Symbolic Logic 2025 Article jsl.2025.16
The class of all ∗-continuous Kleene algebras, whose description includes an infinitary condition on the iteration operator, plays an important role in computer science. The complexity of reasoning in such algebras — ranging from the equational theory to the Horn one, with restricted fragments of the latter in between — was analyzed by Kozen (2002). This ...
Added: August 12, 2026
Speranski S. O., Математические заметки 2026 Т. 120 № 3 С. 470–483
We show that, in terms of closure ordinals, many infinitary calculi for ‘first-order’ logics of probability (i.e., for languages similar to those in [Abadi & Halpern 1994]) are as hard as possible: the corresponding closure ordinals coincide with the least non-constructive ordinal, denoted by $\omega_1^{\mathrm{CK}}$. ...
Added: August 12, 2026
Speranski S. O., Grefenshtein A., Izvestiya. Mathematics 2026 Vol. 90 No. 4 P. 754–775
The article is concerned with Halpern's first-order logics of probability, which we denote by L_1 and L_2 – the first of these deals with probability distributions on the domain, while the second employs distributions on external sets of possible worlds. The proofs of [Abadi & Halpern 1994] of the complexity lower bound results for L_1 and L_2 ...
Added: August 12, 2026
David J. L., Leonid Grinin, Korotayev A., , in: Complexity in Universal Evolution. A Big History Perspective.: Springer, 2026. Ch. 22 P. 585–608.
This collective monograph explores focus on complexity aspects in Big History against the background of complexity growth in the Universe, on our planet, and in biological, social, and cultural systems. Complexity growth is regarded as the connecting thread of evolutionary development and as a leading trend of Big History. The cosmic development chapters examine symmetries ...
Added: August 10, 2026
Korotayev A., , in: Complexity in Universal Evolution. A Big History Perspective.: Springer, 2026. Ch. 13 P. 359–409.
We have undertaken an attempt to propose a periodization of the Big History Biosocial (Anthropogenesis) Era on the basis of the most recent scientific data. This periodization is complexity-based, that is, the boundaries of the identified epochs are marked with complexity jumps, that is, in our case, such phase transitions that result in significant increases ...
Added: August 10, 2026
Leonid Grinin, Alexander M., Korotayev A., , in: Complexity in Universal Evolution. A Big History Perspective.: Springer, 2026. Ch. 12 P. 283–355.
In the first half of this chapter, Grinin et al. survey general similarities and differences between biological and social macroevolution. They undertake a systematic comparison between biological and social evolution at different levels of analysis and in various aspects, formulating a considerable number of general principles and rules of evolution, and working to develop a ...
Added: August 10, 2026
David J. L., Leonid Grinin, Korotayev A., , in: Complexity in Universal Evolution. A Big History Perspective.: Springer, 2026. Ch. 1 P. 1–25.
Complexity is widely acknowledged as a foundational and pivotal concept in Big History, offering a unifying lens through which to examine the emergence and development of systems—from particles and galaxies to life, civilizations, and beyond. Yet, despite its centrality, major gaps remain in how we define, measure, and interpret complexity across different phases and scales. ...
Added: August 10, 2026
Dudakov S., Lobachevskii Journal of Mathematics 2025 Vol. 46 No. 12 P. 6092–6102
We study the additive theory of arbitrary figures in linear spaces, that is, the theory of
addition extended to sets of vectors. Our main result is the following: if a linear space is infinite,
then the additive theory of figures admits interpreting second-order arithmetic and, therefore, it has
such or higher degree of undecidability. For countably infinite spaces, ...
Added: May 1, 2026
Tiskin D., М.: Издательская группа URSS, 2026.
Предлагаемая книга представляет собой введение в формальную семантику — раздел языкознания, в котором посредством построения математически строгих моделей исследуется, как предложения приобретают значение и способность передавать информацию в зависимости от своей структуры и значений составляющих их слов. Классические теоретические идеи Г. Фреге, Д. Льюиса, Д. Каплана и др. излагаются современным языком, а при разработке нотации акцент сделан на том, ...
Added: March 17, 2026
Yerbolova A. S., Tomashchuk K., Kogan A. et al., Complexity 2026 Vol. 2026 No. 1 Article 5519690
Tis paper presents a novel approach to analyzing and grouping natural languages based on the degree of their chaoticity. It clusters 52 languages from 18 language families, according to the value of the entropy–complexity pair, to reveal the chaotic properties of semantic trajectories. Te obtained clusters appear to be closely correlated with the family of ...
Added: February 16, 2026
Speranski S. O., Journal of Logic and Computation 2013 Vol. 23 No. 5 P. 1035–1055
In the present article, the quantifiers over propositions are first introduced into the language for reasoning about probability, then the complexity issues for validity problems dealing with the corresponding hierarchy of probabilistic sentences are investigated. We prove, among other things, the $\Pi^1_1$-completeness for the general validity and also indicate the least level in the hierarchy ...
Added: December 27, 2025
Speranski S. O., Computability 2015 Vol. 4 No. 2 P. 159–174
Added: December 27, 2025
Speranski S. O., Studia Logica 2017 Vol. 105 No. 2 P. 407–429
The paper contains a survey on the complexity of various truth hierarchies arising in Kripke’s theory. I present some new arguments, and use them to obtain a number of interesting generalisations of known results. These arguments are both relatively simple, involving only the basic machinery of constructive ordinals, and very general. ...
Added: December 26, 2025
Speranski S. O., Mathematical Structures in Computer Science 2017 Vol. 27 No. 8 P. 1581–1600
In this article we describe a bunch of probability logics with quantifiers over events, and develop primary techniques for proving computational complexity results (in terms of m-degrees) about these logics, mainly over discrete probability spaces. Also the article contains a comparison with some other probability logics and a discussion of interesting analogies with research in the metamathematics ...
Added: December 26, 2025
Speranski S. O., Journal of Logic and Computation 2021 Vol. 31 No. 5 P. 1330–1355
The idea of treating negation as a modality manifests itself in various logical systems, especially in Došen's propositional logic N, whose negation is weaker than that of Johansson's minimal logic. Among the interesting extensions of N are the propositional logics N* and Hype; the former was proposed in [Cabalar et al. 2006], while the latter has ...
Added: December 26, 2025
Kuznetsov S., Speranski S. O., Annals of Pure and Applied Logic 2022 Vol. 173 No. 2 Article 103057
We introduce infinitary action logic with exponentiation — that is, the multiplicative-additive Lambek calculus extended with Kleene star and with a family of subexponential modalities, which allow some of the structural rules (contraction, weakening, permutation). The logic is presented in the form of an infinitary sequent calculus. We prove cut elimination and, in the case ...
Added: December 26, 2025
Kuznetsov S., Speranski S. O., Studia Logica 2023 Vol. 111 No. 2 P. 251–280
Infinitary action logic can be naturally expanded by adding exponential and subexponential modalities from linear logic. In this article we shall develop infinitary action logic with a subexponential that allows multiplexing (instead of contraction). Both non-commutative and commutative versions of this logic will be considered, presented as infinitary sequent calculi. We shall prove cut admissibility ...
Added: December 26, 2025