Logic and Logical Philosophy
https://apcz.umk.pl/LLP
<p><em>Logic and Logical Philosophy</em> is a journal chiefly devoted to philosophical logic and philosophy, which results from applying logical tools to philosophical problems. Other applications of logic to related disciplines are not excluded.</p> <p><strong>Journal Metrics 2023</strong></p> <table width="400"> <tbody> <tr> <td>Journal Impact Factor (JIF)</td> <td>0.6</td> <td>Q2; percentile: 62</td> </tr> <tr> <td>5-Year Impact Factor</td> <td>0.6</td> <td>N/A</td> </tr> <tr> <td>Journal Citation Indicator (JCI)</td> <td>0.86</td> <td>Q1; percentile: 78</td> </tr> <tr> <td>Scopus CiteScore™</td> <td>1.0</td> <td>Q2; percentile: 73</td> </tr> <tr> <td>SNIP</td> <td>0.61</td> <td>N/A</td> </tr> <tr> <td>SJR</td> <td>0.45</td> <td>Q1</td> </tr> </tbody> </table> <p> </p>Uniwersytet Mikołaja Kopernika w Toruniuen-USLogic and Logical Philosophy1425-3305A Misleading Triviality Argument in the Theory of Conditionals
https://apcz.umk.pl/LLP/article/view/43755
<p>PCCP is the much discussed claim that the probability of a conditional A → B is conditional probability. Triviality results purport to show that PCCP – as a general claim – is false. A particularly interesting proof has been presented in (Hájek, 2011), who shows that – even if a probability distribution P initially satisfied PCCP – a rational update can produce a non-PCCP probability distribution.</p> <p>We argue that the notion of rational update in this argumentation is construed in much too broad a way. In order to make the argumentation precise, we discuss the general rules for modeling conditionals in probability spaces and present formalized version(s) of PCCP and of minimal assumptions concerning the appropriate spaces. Using the introduced apparatus we give a detailed analysis of Hájek’s (2011) triviality proof and show that it is based on an application of revision rules which allow one to construct probability distributions violating not only PCCP, but also fundamental properties of conditionals.</p> <p>This means that they do not really provide arguments against PCCP, properly formalized. We also discuss a Dutch Book argument which shows that the updated belief system is not coherent. This gives an additional, strong argument against accepting the update rules. We also discuss the Converse Dutch Book theorem and argue, that even if the produced probability measure seems to violate it, it cannot serve as the counterexample, as it is not an appropriate model for conditionals. Ultimately, we show that important arguments against PCCP fail.</p>Anna WójtowiczKrzysztof Wójtowicz
Copyright (c) 2024 Anna Wójtowicz, Krzysztof Wójtowicz
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2024-05-042024-05-0433334938010.12775/LLP.2024.015Justification Logic and the Epistemic Contribution of Deduction
https://apcz.umk.pl/LLP/article/view/40913
<p>Accounting for the epistemic contribution of deduction has been a pervasive problem for logicians interested in deduction, such as, among others, Jakko Hintikka. The problem arises because the conclusion validly deduced from a set of premises is said to be “contained” in that set; because of this containment relation, the conclusion would be known from the moment the premises are known. Assuming this, it is problematic to explain how we can gain knowledge by deducing a logical consequence implied by a set of known premises. To address this problem, we offer an alternative account of the epistemic contribution of deduction as the process required to deduce a conclusion or a theorem, understanding such a process not only in terms of the number of steps in the derivation but also, more importantly, in terms of the reason for or justification for every step. That is, we do not know a proposition unless we have a justification or proof of that proposition. With this goal in mind, we develop a justification logic system which exhibits the epistemic contribution of a deductive derivation as the resulting justified formula.</p>Nancy Abigail Nuñez HernándezFrancisco Hernández-Quiroz
Copyright (c) 2024 Nancy Abigail Nuñez Hernández, Francisco Hernández-Quiroz
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2024-03-042024-03-0433338140210.12775/LLP.2024.011If You’re Happy, Then You Know It: The Logic of Happiness . . . and Sadness
https://apcz.umk.pl/LLP/article/view/44935
<p>The article proposes a formal semantics of happiness and sadness modalities in the imperfect information setting. It shows that these modalities are not definable through each other and gives a sound and complete axiomatization of their properties.</p>Sanaz Azimipour Pavel Naumov
Copyright (c) 2024 Sanaz Azimipour , Pavel Naumov
https://creativecommons.org/licenses/by-nd/4.0
2024-02-052024-02-0533340346210.12775/LLP.2024.009Uniform Cut-Free Bisequent Calculi for Three-Valued Logics
https://apcz.umk.pl/LLP/article/view/47308
<p>We present a uniform characterisation of three-valued logics by means of a bisequent calculus (BSC). It is a generalised form of a sequent calculus (SC) where rules operate on the ordered pairs of ordinary sequents. BSC may be treated as the weakest kind of system in the rich family of generalised SC operating on items being some collections of ordinary sequents, like hypersequent and nested sequent calculi. It seems that for many non-classical logics, including some many-valued, paraconsistent and modal logics, the reasonably modest generalisation of standard SC offered by BSC is sufficient. In this paper, we examine a variety of three-valued logics and show how they can be formalised in the framework of BSC. We present a constructive syntactic proof that these systems are cut-free, satisfy the subformula property, and allow one to prove the interpolation theorem in many cases.</p>Andrzej IndrzejczakYaroslav Petrukhin
Copyright (c) 2024 Andrzej Indrzejczak, Yaroslav Petrukhin
https://creativecommons.org/licenses/by-nd/4.0
2024-07-262024-07-2633346350610.12775/LLP.2024.019