Referential semantics importantly subscribes to the programme of theory of logical calculi. Defined by Wójcicki in [8], it has been subsequently studied in a series of papers of the author, till the full exposition of the framework in [9] and its intuitive characterisation in [10]. The aim of the article is to present several generalizations of referential semantics as compared and related to the matrix semantics for propositional logics. We show, in a uniform way, some own (...) generalizations of referentiality: the first, directed to unrestricted cluster referential semantics, [4], its "discrete" version, a counterpart of algebraic semantics and a many-valued referentiality based on matrices, whose elements are functions from the set of indices to a finite n-element set of values, n≥2, [3]. Next to this we outline pragmatic matrices introduced by Tokarz in [6] as an alternative for cluster referential approach and discuss together all presented versions of referential semantics. (shrink)

Referential matrix semantics of R. W´ojcicki [5] and [4] is extended to cover the class of all structural propositional calculi.

In [7] Wojtylak showed that the supremum of a finite collection of strongly finite logics is not necessarily strongly finite, putting to an end the dispute concerning the underlying algebraic structure of the set of all strongly finite logics defined on a propositional language. In this paper we prove that Wojtylak’s result extends to a wider class of propositional logics defined by finite sets of finite matrices with admissible valuations.

Implicational tonoid logics and their extensions with abstract Galois properties have been introduced by Yang and Dunn. They introduced matrix semantics for the implicational tonoid logics but did not do for the extensions. Here we provide such semantics for implicational partial gaggle logics as one sort of such extensions. To this end, first we discuss implicational partial gaggle logics in Hilbert-style. We next introduce one kind of matrix semantics based on Lindenbaum– Tarski matrices for the (...) logics and show that those logics are complete with respect to the matrix semantics. Finally, we further introduce a slightly different kind of matrix semantics based on reduced models for the logics and show that those logics are complete with respect to this matrix semantics. (shrink)

This paper is a sequel to ‘Belnap-Dunn semantics for natural implicative expansions of Kleene's strong three-valued matrix with two designated values’, where a ‘bivalent’ Belnap-Dunn semantics is provided for all the expansions referred to in its title. The aim of the present paper is to carry out a parallel investigation for all natural implicative expansions of Kleene's strong 3-valued matrix now with only one designated value.

Very often logics are dened by means of the axiomatic method which depends, roughly speaking, on selecting some set of axiom schemas together with certain rules of inferences; here we consider only log- ics that are dened in this way. The representative examples are: E, R and INT. In the case of E and R the modus ponens rule and the rule of adjunction are used, while for INT the modus ponens only; all of them, of course, together with some (...) nite set of axiom schemas. Therefore, with each logic, say L by the proof-theoretical notion we as- sociate the structural consequence operation, denoted by CL. For instance, the exact denition of CE looks as follows: for all X and ; 2 CE i can be provable from X by applications of some instan. (shrink)

ABSTRACTA conditional is natural if it fulfils the three following conditions. It coincides with the classical conditional when restricted to the classical values T and F; it satisfies the Modus Ponens; and it is assigned a designated value whenever the value assigned to its antecedent is less than or equal to the value assigned to its consequent. The aim of this paper is to provide a ‘bivalent’ Belnap-Dunn semantics for all natural implicative expansions of Kleene's strong 3-valued matrix (...) with two designated elements. (shrink)

We provide a logical matrix semantics and a Gentzen-style sequent calculus for the first-degree entailments valid in W. T. Parry’s logic of Analytic Implication. We achieve the former by introducing a logical matrix closely related to that inducing paracomplete weak Kleene logic, and the latter by presenting a calculus where the initial sequents and the left and right rules for negation are subject to linguistic constraints.

This work adapts techniques and results first developed by Malinowski and by Marek in the context of referential semantics of sentential logics to the context of logics formalized as π-institutions. More precisely, the notion of a pseudoreferential matrix system is introduced and it is shown how this construct generalizes that of a referential matrix system. It is then shown that every π–institution has a pseudo-referential matrix system semantics. This contrasts with referential matrix system (...) class='Hi'>semantics which is only available for self-extensional π-institutions by a previous result of the author obtained as an extension of a classical result of Wójcicki. Finally, it is shown that it is possible to replace an arbitrary pseudoreferential matrix system semantics by a discrete pseudo-referential matrix system semantics. (shrink)

The paper offers a matrix-based logic (relevant matrix quantum physics) for propositions which seems suitable as an underlying logic for empirical sciences and especially for quantum physics. This logic is motivated by two criteria which serve to clean derivations of classical logic from superfluous redundancies and uninformative complexities. It distinguishes those valid derivations (inferences) of classical logic which contain superfluous redundancies and complexities and are in this sense from those which are or in the sense of allowing only (...) the most informative consequences in the derivations. The latter derivations are strictly valid in RMQ, whereas the former are only materially valid. RMQ is a decidable matrix calculus which possesses a semantics and has the finite model property. It is shown in the paper how RMQ by its strictly valid derivations can avoid the difficulties with commensurability, distributivity, and Bell's inequalities when it is applied to quantum physics. (shrink)

We define and study abstract valuation semantics for logics, an algebraically well-behaved version of valuation semantics. Then, in the context of the behavioral approach to the algebraization of logics, we show, by means of meaningful bridge theorems and application examples, that abstract valuations are suited to play a role similar to the one played by logical matrices in the traditional approach to algebraization.

The range of research on value issues is quite wide today. The transition from understanding values as a philosophical category to a psychological interpretation of the nature of values has led to the emergence of many trends and psychological concepts of value problems. In this study, we will reveal the main modern views of researchers on the essence of the value-semantic matrix of both an individual and the entire world community. The modern socio-economic situation in the world is characterized (...) by an almost permanent crisis state both in the social, and in the spiritual, cultural sphere, which is due to the existence of the consequences of the epidemic situation in the world. Based on this, the problem of teaching the dynamics of the value-semantic matrix, its development and changes under the influence of personality crises of various origins, both external ones caused by the social situation in the country, the impact of new information technologies, and internal ones, caused by growing up, growth, psychological development personality in time and space. Therefore, the purpose of this work is to conduct a theoretical study of the value-semantic sphere as a system that undergoes changes during the crisis periods of a person's life and to investigate the main deformations that have taken place in the Mind of existence of today's post-pandemic reality. (shrink)

Cognition is both empowered and limited by representations. The matrix lens model explicates tasks that are based on frequency counts, conditional probabilities, and binary contingencies in a general fashion. Based on a structural analysis of such tasks, the model links several problems and semantic domains and provides a new perspective on representational accounts of cognition that recognizes representational isomorphs as opportunities, rather than as problems. The shared structural construct of a 2 × 2 matrix supports a set of (...) generic tasks and semantic mappings that provide a unifying framework for understanding problems and defining scientific measures. Our model's key explanatory mechanism is the adoption of particular perspectives on a 2 × 2 matrix that categorizes the frequency counts of cases by some condition, treatment, risk, or outcome factor. By the selective steps of filtering, framing, and focusing on specific aspects, the measures used in various semantic domains negotiate distinct trade-offs between abstraction and specialization. As a consequence, the transparent communication of such measures must explicate the perspectives encapsulated in their derivation. To demonstrate the explanatory scope of our model, we use it to clarify theoretical debates on biases and facilitation effects in Bayesian reasoning and to integrate the scientific measures from various semantic domains within a unifying framework. A better understanding of problem structures, representational transparency, and the role of perspectives in the scientific process yields both theoretical insights and practical applications. (shrink)

. In our paper, presented here in abstract form, we consider the sentential logic with semi-negation. It should be stressed, however, that our main interest is not that logic itself but rather more general matters concerning the theory of matrix semantics for sentential logics. The logic with semi-negation provides a relevant example for elucidating such basic notions of matrix semantics as degree of complexity, degree of uniformity, and self-referentiality. Thus our paper being a contribution to the (...) theory of matrix semantics may be treated as a sequel to [1]. (shrink)

The aim of this paper is to show that the operations of forming direct products and submatrices suffice to construct exhaustive semantics for all structural strengthenings of the consequence determined by a given class of logical matrices.

The plurivalent logics considered in Graham Priest's recent paper of that name can be thought of as logics determined by matrices whose underlying algebras are power algebras, where the power algebra of a given algebra has as elements textit{subsets} of the universe of the given algebra, and the power matrix of a given matrix has has the power algebra of the latter's algebra as its underlying algebra, with its designated elements being selected in a natural way on the (...) basis of those of the given matrix. The present discussion stresses the continuity of Priest's work on the question of which matrices determine consequence relations which remain unaffected on passage to the consequence relation determined by the power matrix of the given matrix with the corresponding question in equational logic as to which identities holding in an algebra continue to hold in its power algebra. Both questions are sensitive to a decision as to whether or not to include the empty set as an element of the power algebra, and our main focus will be on the contrast, when it is included, between the power matrix semantics and the four-valued Dunn--Belnap semantics for first-degree entailment a la Anderson and Belnap) in terms of sets of classical values, in which the empty set figures in a somewhat different way, as Priest had remarked his 1984 study, `Hyper-contradictions', in which what we are calling the power matrix construction first appeared. (shrink)

Semantyka teoriomonogościowa dla wielowartościowych rachunków pozycyjnych Celem artykułu jest zdefiniowanie adekwatnych semantyk teoriomonogościowych dla rachunków pozycyjnych.

One of the most important paraconsistent logics is the logic mCi, which is one of the two basic logics of formal inconsistency. In this paper we present a 5-valued characteristic nondeterministic matrix for mCi. This provides a quite non-trivial example for the utility and effectiveness of the use of non-deterministic many-valued semantics.

In this paper, we define the family FiCn:={FiCn}n∈ω of logics by means of semantics of bivaluations. This family is a variant of the family of paraconsistent bivaluated Ciun-logics, defined and studied by J. Ciuciura. We will show that every logic in FiCn can be alternatively defined by means of finite matrices. This result arises from the characterisation of the truth-values of the involved matrices (relative to each FiCn-logic) as being specific finite sequences of elements of the set 2 := (...) {0,1}. Moreover, we will show in this paper that such characterisation is related to the well-known standard Fibonacci Sequence, which is presented here by means of its binary expansion. (shrink)

Corpus-assisted analyses of public discourse often focus on the lexical level. This article argues in favour of corpus-assisted analyses of discourse, but also in favour of conceptualising salient lexical items in public discourse in a more determined way. It draws partly on non-Anglophone academic traditions in order to promote a conceptualisation of discourse keywords, thereby highlighting how their meaning is determined by their use in discourse contexts. It also argues in favour of emphasising the cognitive and epistemic dimensions of discourse-determined (...) semantic structures. These points will be exemplified by means of a corpus-assisted, as well as a frame-based analysis of the discourse keyword financial crisis in British newspaper articles from 2009. Collocations of financial crisis are assigned to a generic matrix frame for ‘event’ which contains slots that specify possible statements about events. By looking at which slots are more, respectively less filled with collocates of financial crisis, we will trace semantic presence as well as absence, and thereby highlight the pragmatic dimensions of lexical semantics in public discourse. The article also advocates the suitability of discourse keyword analyses for systematic contrastive analyses of public/political discourse and for lexicographical projects that could serve to extend the insights drawn from corpus-guided approaches to discourse analysis. (shrink)

In the first part of this paper we analyzed finite non-deterministic matrix semantics for propositional non-normal modal logics as an alternative to the standard Kripke possible world semantics. This kind of modal system characterized by finite non-deterministic matrices was originally proposed by Ju. Ivlev in the 70s. The aim of this second paper is to introduce a formal non-deterministic semantical framework for the quantified versions of some Ivlev-like non-normal modal logics. It will be shown that several well-known (...) controversial issues of quantified modal logics, relative to the identity predicate, Barcan’s formulas and de re and de dicto modalities, can be tackled from a new angle within the present framework. (shrink)

This paper delves into the temporal interpretation of fronting constructions in English, a topic that has received limited attention in the literature on tense semantics. It presents new empirical findings revealing that specific fronting configurations, involving present tense morphology in a complement CP under a matrix past tense, can yield a theoretically unexpected simultaneous interpretation. A novel theoretical framework for understanding English tense is proposed, which accounts for the temporal interpretation of both fronting and non-fronting versions of attitude (...) reports. The framework introduces a null simultaneous tense as a replacement for the conventional indexical present and the Sequence-of-Tense (SOT) _de se_ tense. It is argued that in complement CPs the null simultaneous tense, as well as past tense, can be anchored either to the attitude time or to the utterance time. In either case, each tense receives a _de re_ interpretation. Moreover, the paper contends that evidence from fronting constructions supports Kratzer’s (Proceedings of semantics and linguistic theory 8, pp. 92–110, 1998 ) proposal that the transmission of temporal features (as part of the mechanism of SOT) occurs at PF. Finally, the proposed revision of the English tense system contributes to a more unified cross-linguistic perspective on tense. It is demonstrated how the temporal readings of attitude reports arising in such non-SOT languages as Russian, Japanese, and Hebrew can be captured within the system developed for English, with known contrasts attributed to the absence of Feature Transmission in those languages. Further known and new data from English, Modern Greek, and German are examined, revealing variations in SOT effects across SOT languages. These data are used as additional evidence supporting the claim that cross-linguistic variation in the interpretation of complement tense stems solely from differences in Feature Transmission. Regarding the semantic profile of tenses, it can be considered largely invariant. (shrink)

The ternary, not binary, Kripke-type relation on a set of possible worlds is an essential part of the semantics of entailment by Routley-Meyer [2]. The unpopularity of such approach among many logicians is due to its intuitive vague content and complexity. An attempt is made to use not one ternary relation but two binary relations and necessity of bibinarness is demonstrated. It is shown that both semantics are equal hence the soundness and completeness of the system R of (...) entailment can be established with the respect to the bibinary semantics. Furthermore, the ternary semantic with discrete matrix for Lukasiewicz system Lℵ0 , which was proposed in [3], could be transformed into the bibinary one and it leads to the conclusion of the completeness and soundness of Lℵ0 with the respect to the bibinary semantic. The brief consideration of the bibinary semantic intuitive content is added, which further logical study could be based on. (shrink)

In order to handle inconsistent knowledge bases in a reasonable way, one needs a logic which allows nontrivial inconsistent theories. Logics of this sort are called paraconsistent. One of the oldest and best known approaches to the problem of designing useful paraconsistent logics is da Costa’s approach, which seeks to allow the use of classical logic whenever it is safe to do so, but behaves completely differently when contradictions are involved. Da Costa’s approach has led to the family of logics (...) of formal (in)consistency (LFIs). In this paper we provide in a modular way simple non-deterministic semantics for 64 of the most important logics from this family. Our semantics is 3-valued for some of the systems, and infinite-valued for the others. We prove that these results cannot be improved: neither of the systems with a three-valued non-deterministic semantics has either a finite characteristic ordinary matrix or a two-valued characteristic non-deterministic matrix, and neither of the other systems we investigate has a finite characteristic non-deterministic matrix. Still, our semantics provides decision procedures for all the systems investigated, as well as easy proofs of important proof-theoretical properties of them. (shrink)

Equivalent overdetermined and underdetermined bivalent Belnap–Dunn type semantics for the logics determined by all natural implicative expansions of Kleene’s strong 3-valued matrix with only one designated value are provided.

A well-known result, going back to the twenties, states that, under some reasonable assumptions, any logic can be characterized as the set of formulas satisfied by a matrix 〈,F〉, whereis an algebra of the appropriate type, andFa subset of the domain of, called the set of designated elements. In particular, every quasi-classical modal logic—a set of modal formulas, containing the smallest classical modal logicE, which is closed under the inference rules of substitution and modus ponens—is characterized by such a (...) matrix, wherenow is a modal algebra, andFis a filter of. If the modal logic is in fact normal, then we can do away with the filter; we can study normal modal logics in the setting of varieties of modal algebras. This point of view was adopted already quite explicitly in McKinsey and Tarski [8]. The observation that the lattice of normal modal logics is dually isomorphic to the lattice of subvarieties of a variety of modal algebras paved the road for an algebraic study of normal modal logics. The algebraic approach made available some general results from Universal Algebra, notably those obtained by Jónsson [6], and thereby was able to contribute new insights in the realm of normal modal logics [2], [3], [4], [10].The requirement that a modal logic be normal is rather a severe one, however, and many of the systems which have been considered in the literature do not meet it. For instance, of the five celebrated modal systems, S1–S5, introduced by Lewis, S4 and S5 are the only normal ones, while only SI fails to be quasi-classical. The purpose of this paper is to generalize the algebraic approach so as to be applicable not just to normal modal logics, but to quasi-classical modal logics in general. (shrink)

In 1988, J. Ivlev proposed some (non-normal) modal systems which are semantically characterized by four-valued non-deterministic matrices in the sense of A. Avron and I. Lev. Swap structures are multialgebras (a.k.a. hyperalgebras) of a special kind, which were introduced in 2016 by W. Carnielli and M. Coniglio in order to give a non-deterministic semantical account for several paraconsistent logics known as logics of formal inconsistency, which are not algebraizable by means of the standard techniques. Each swap structure induces naturally a (...) non-deterministic matrix. The aim of this paper is to obtain a swap structures semantics for some Ivlev-like modal systems proposed in 2015 by M. Coniglio, L. Fariñas del Cerro and N. Peron. Completeness results will be stated by means of the notion of Lindenbaum–Tarski swap structures, which constitute a natural generalization to multialgebras of the concept of Lindenbaum–Tarski algebras. (shrink)

In 1960, A. N. Prior proposed a binary sentential functor defined by inferential rule (introduction) A ⊢ A tonk B, and (elimination) A tonk B ⊢ A. Later, this idea was discussed by several authors, including in the context of the question of whether the ab ove rule defines this functor in a sufficient manner. This paper shows that if we assume the standard matrix (truth-tables) characterization of classical sentential functors, no valuation agrees with rules generating the sense of (...) tonk. Moreover, these inferential prescriptions are at odds with the principle that if premises are true, the conclusion has to be such as well. A new solution is proposed. It consists in considering tonk-rules via so-called rejection consequence operation, that is, a dual with respect to the standard Cn. The general moral stemming from the proposed analysis says that inferentialism, the view that inference rules are purely syntactical, is dubious, because logic has its basis also in semantic presuppositions as well as in pragmatic ones. (shrink)

An (n, k)-ary quantifier is a generalized logical connective, binding k variables and connecting n formulas. Canonical systems with (n, k)-ary quantifiers form a natural class of Gentzen-type systems which in addition to the standard axioms and structural rules have only logical rules in which exactly one occurrence of a quantifier is introduced. The semantics for these systems is provided using two-valued non-deterministic matrices, a generalization of the classical matrix. In this paper we use a constructive syntactic criterion (...) of coherence to characterize strong cutelimination in such systems. We show that the following properties of a canonical system G with arbitrary (n, k)-ary quantifiers are equivalent: (i) G is coherent, (ii) G admits strong cut-elimination, and (iii) G has a strongly characteristic two-valued generalized non-deterministic matrix. (shrink)

The neural blackboard architecture is a localist structured connectionist model that employs a novel connection matrix to implement dynamic bindings without requiring propagation of temporal synchrony. Here I note the apparent need for many distinct matrices and the effect this might have for scale-up to semantic processing. I also comment on the authors' initial foray into the symbol grounding problem.

In this work, we discuss the failure of the principle of truth functionality in the quantum formalism. By exploiting this failure, we import the formalism of N-matrix theory and non-deterministic semantics to the foundations of quantum mechanics. This is done by describing quantum states as particular valuations associated with infinite non-deterministic truth tables. This allows us to introduce a natural interpretation of quantum states in terms of a non-deterministic semantics. We also provide a similar construction for arbitrary (...) probabilistic theories based in orthomodular lattices, allowing to study post-quantum models using logical techniques. (shrink)

In this text, a variety of modal logics at the sentential, first-order, and second-order levels are developed with clarity, precision and philosophical insight. All of the S1-S5 modal logics of Lewis and Langford, among others, are constructed. A matrix, or many-valued semantics, for sentential modal logic is formalized, and an important result that no finite matrix can characterize any of the standard modal logics is proven. Exercises, some of which show independence results, help to develop logical skills. (...) A separate sentential modal logic of logical necessity in logical atomism is also constructed and shown to be complete and decidable. On the first-order level of the logic of logical necessity, the modal thesis of anti-essentialism is valid and every de re sentence is provably equivalent to a de dicto sentence. An elegant extension of the standard sentential modal logics into several first-order modal logics is developed. Both a first-order modal logic for possibilism containing actualism as a proper part as well as a separate modal logic for actualism alone are constructed for a variety of modal systems. Exercises on this level show the connections between modal laws and quantifier logic regarding generalization into, or out of, modal contexts and the conditions required for the necessity of identity and non-identity. Two types of second-order modal logics, one possibilist and the other actualist, are developed based on a distinction between existence-entailing concepts and concepts in general. The result is a deeper second-order analysis of possibilism and actualism as ontological frameworks. Exercises regarding second-order predicate quantifiers clarify the distinction between existence-entailing concepts and concepts in general. Modal Logic is ideally suited as a core text for graduate and undergraduate courses in modal logic, and as supplementary reading in courses on mathematical logic, formal ontology, and artificial intelligence. (shrink)

For decades Ryszard Wójcicki has been a highly influential scholar in the community of logicians and philosophers. Our aim is to outline and comment on some essential issues on logic, methodology of science and semantics as seen from the perspective of distinguished contributions of Wójcicki to these areas of philosophical investigations.

We extend meet-combination of logics for capturing the consequences that are common to both logics. With this purpose in mind we define meet-combination of consequence systems. This notion has the advantage of accommodating different ways of presenting the semantics and the deductive calculi. We consider consequence systems generated by a matrix semantics and consequence systems generated by Hilbert calculi. The meet-combination of consequence systems generated by matrix semantics is the consequence system generated by their product. (...) On the other hand, the meet-combination of consequence systems generated by Hilbert calculi is the consequence system generated by their interconnection. We investigate preservation of several properties. Capitalizing on these results we show that interconnection provides an axiomatization for the product. Illustrations are given for intuitionistic and modal logics, Łukasiewicz logic and some paraconsistent logics. (shrink)

In this paper it is argued that herzberger's general theory of presupposition may be successfully applied to category mistakes. The study offers an alternative to thomason's supervaluation treatment of sortal presupposition and as an indirect measure of the relative merits of the two-Dimensional theory to supervaluations. Bivalent, Three-Valued matrix, And supervaluation accounts are compared to the two-Dimensional theory according to three criteria: (1) abstraction from linguistic behavior, (2) conformity of technical to preanalytic distinctions, And (3) ability to capture classical (...) logic. A matrix like characterization of thomason's theory is reported. (shrink)

Wójcicki has provided a characterization of selfextensional logics as those that can be endowed with a complete local referential semantics. His result was extended by Jansana and Palmigiano, who developed a duality between the category of reduced congruential atlases and that of reduced referential algebras over a fixed similarity type. This duality restricts to one between reduced atlas models and reduced referential algebra models of selfextensional logics. In this paper referential algebraic systems and congruential atlas systems are introduced, which (...) abstract referential algebras and congruential atlases, respectively. This enables the formulation of an analog of Wójcicki’s Theorem for logics formalized as π-institutions. Moreover, the results of Jansana and Palmigiano are generalized to obtain a duality between congruential atlas systems and referential algebraic systems over a fixed categorical algebraic signature. In future work, the duality obtained in this paper will be used to obtain one between atlas system models and referential algebraic system models of an arbitrary selfextensional π-institution. Using this latter duality, the characterization of fully selfextensional deductive systems among the selfextensional ones, that was obtained by Jansana and Palmigiano, can be extended to a similar characterization of fully selfextensional π-institutions among appropriately chosen classes of selfextensional ones. (shrink)

Research focusing on Anglo-European languages indicates that children’s acquisition of the subordinate structure of complement-clause constructions and the semantics of mental verbs facilitates their understanding of false belief, and that the two linguistic factors interact. Complement-clause constructions support false-belief development, but only when used with realis mental verbs like ‘think’ in the matrix clause (de Villiers, Jill. 2007. The interface of language and Theory of Mind.Lingua117(11). 1858–1878). In Chinese, however, only the semantics of mental verbs seems to (...) play a facilitative role in false-belief development (Cheung, Him, Hsuan-Chih Chen & William Yeung. 2009. Relations between mental verb and false belief understanding in Cantonese-speaking children.Journal of Experimental Child Psychology104(2). 141–155). We argue that these cross-linguistic differences can be explained by variations in availability and usage patterns of mental verbs and complement-clause constructions across languages. Unlike English, Mandarin-Chinese has a verb that indicates that a belief might be false:yi3wei2‘(falsely) think’. Our corpus analysis suggests that, unlike English caregivers, Mandarin-Chinese caregivers do not produce frequent, potentially unanalyzed, chunks with mental verbs and first-person subjects, such as ‘I think’. In an experiment, we found that the comprehension of complement-clause constructions used withyi3wei2‘(falsely) think’, but not withjue2de2‘think’, predicted Mandarin children’s false-belief understanding between the ages of 4 and 5. In contrast to English, whether mental verbs were used with first- or third-person subjects did not affect their correlation with false-belief understanding. (shrink)

Maximality is a desirable property of paraconsistent logics, motivated by the aspiration to tolerate inconsistencies, but at the same time retain from classical logic as much as possible. In this paper we introduce the strongest possible notion of maximal paraconsistency, and investigate it in the context of logics that are based on deterministic or non-deterministic three-valued matrices. We show that all reasonable paraconsistent logics based on three-valued deterministic matrices are maximal in our strong sense. This applies to practically all three-valued (...) paraconsistent logics that have been considered in the literature, including a large family of logics which were developed by da Costa's school. Then we show that in contrast, paraconsistent logics based on three-valued properly nondeterministic matrices are not maximal, except for a few special cases (which are fully characterized). However, these non-deterministic matrices are useful for representing in a clear and concise way the vast variety of the (deterministic) three-valued maximally paraconsistent matrices. The corresponding weaker notion of maximality, called premaximal paraconsistency, captures the "core" of maximal paraconsistency of all possible paraconsistent determinizations of a non-deterministic matrix, thus representing what is really essential for their maximal paraconsistency. (shrink)

Dugundji proved in 1940 that most parts of standard modal systems cannot be characterized by a single finite deterministic matrix. In the eighties, Ivlev proposed a semantics of four-valued non-deterministic matrices, in order to characterize a hierarchy of weak modal logics without the necessitation rule. In a previous paper, we extended some systems of Ivlev’s hierarchy, also proposing weaker six-valued systems in which the axiom was replaced by the deontic axiom. In this paper, we propose even weaker systems, (...) by eliminating both axioms, which are characterized by eight-valued non-deterministic matrices. In addition, we prove completeness for those new systems. It is natural to ask if a characterization by finite ordinary logical matrices would be possible for all those Ivlev-like systems. We will show that finite deterministic matrices do not characterize any of them. (shrink)

We extend classical work by Janusz Czelakowski on the closure properties of the class of matrix models of entailment relations—nowadays more commonly called multiple-conclusion logics—to the setting of non-deterministic matrices (Nmatrices), characterizing the Nmatrix models of an arbitrary logic through a generalization of the standard class operators to the non-deterministic setting. We highlight the main differences that appear in this more general setting, in particular: the possibility to obtain Nmatrix quotients using any compatible equivalence relation (not necessarily a congruence); (...) the problem of determining when strict homomorphisms preserve the logic of a given Nmatrix; the fact that the operations of taking images and preimages cannot be swapped, which determines the exact sequence of operators that generates, from any complete semantics, the class of all Nmatrix models of a logic. Many results, on the other hand, generalize smoothly to the non-deterministic setting: we show for instance that a logic is finitely based if and only if both the class of its Nmatrix models and its complement are closed under ultraproducts. We conclude by mentioning possible developments in adapting the Abstract Algebraic Logic approach to logics induced by Nmatrices and the associated equational reasoning over non-deterministic algebras. (shrink)

This paper concerns the interface between relevant logics and recent developments in semantics for hyperintensional operators. In the latter area, the notion of topicality or aboutness has begun to play an explicit modeling role, with classes of models being studied which incorporate representations of topics, and of operations on topics. The idea is to use these topics in the evaluations of formulas including hyperintensional operators in order to explain why classically equivalent formulas may not be intersubstitutable in contexts using (...) those operators—though classically equivalent, if a pair of formulas can be interpreted to concern totally unrelated topics, then we should not be able to substitute one for the other in contexts which are sensitive to topics. Relevant logics, and the central relevance property of Variable Sharing, have been read as concerning something like topics in the past, and recently this angle on relevance has seen renewed interest. In this paper, I’ll develop and motivate a method for representing topics in the matrix models of logics, and apply this method to _R_ and its matrix models (given by De Morgan monoids) to argue that there is a clear semantic perspective on topicality according to which _R_ is topic-sensitive as a logic. (shrink)

An (n, k)-ary quantifier is a generalized logical connective, binding k variables and connecting n formulas. Canonical systems with (n, k)-ary quantifiers form a natural class of Gentzen-type systems which in addition to the standard axioms and structural rules have only logical rules in which exactly one occurrence of a quantifier is introduced. The semantics for these systems is provided using two-valued non-deterministic matrices, a generalization of the classical matrix. In this paper we use a constructive syntactic criterion (...) of coherence to characterize strong cutelimination in such systems. We show that the following properties of a canonical system G with arbitrary (n, k)-ary quantifiers are equivalent: (i) G is coherent, (ii) G admits strong cut-elimination, and (iii) G has a strongly characteristic two-valued generalized non-deterministic matrix. In addition, we define simple calculi, an important subclass of canonical calculi, for which coherence is equivalent to the weaker, standard cut-elimination property. (shrink)

A canonical Gentzen-type system is a system in which every rule has the subformula property, it introduces exactly one occurrence of a connective, and it imposes no restrictions on the contexts of its applications. A larger class of Gentzen-type systems which is also extensively in use is that of quasi-canonical systems. In such systems a special role is given to a unary connective \ of the language. Accordingly, each application of a logical rule in such systems introduces either a formula (...) of the form \\), or of the form \\), and all the active formulas of its premises belong to the set \. In this paper we investigate the whole class of quasi-canonical systems. We provide a constructive coherence criterion for such systems, and show that a quasi-canonical system is coherent iff it is analytic iff it has a characteristic non-deterministic matrix which is based on some subset of the set of the four truth-values which are used in the famous Dunn–Belnap four-valued matrix for information processing. In addition, we determine when a quasi-canonical system admits cut-elimination. (shrink)

We study the algebraizability of the logics constructed using literal-paraconsistent and literal-paracomplete matrices described by Lewin and Mikenberg in [11], proving that they are all algebraizable in the sense of Blok and Pigozzi in [3] but not finitely algebraizable. A characterization of the finitely algebraizable logics defined by LPP-matrices is given.We also make an algebraic study of the equivalent algebraic semantics of the logics associated to the matrices ℳ32,2, ℳ32,1, ℳ31,1, ℳ31,3, and ℳ4 appearing in [11] proving that they (...) are not varieties and finding the free algebra over one generator. (shrink)