26 found
Order:
  1.  47
    Neighbourhood Semantics for Quantified Relevant Logics.Andrew Tedder & Nicholas Ferenz - 2022 - Journal of Philosophical Logic 51 (3):457-484.
    The Mares-Goldblatt semantics for quantified relevant logics have been developed for first-order extensions of R, and a range of other relevant logics and modal extensions thereof. All such work has taken place in the the ternary relation semantic framework, most famously developed by Sylvan and Meyer. In this paper, the Mares-Goldblatt technique for the interpretation of quantifiers is adapted to the more general neighbourhood semantic framework, developed by Sylvan, Meyer, and, more recently, Goble. This more algebraic semantics allows one to (...)
    Direct download (3 more)  
     
    Export citation  
     
    Bookmark   4 citations  
  2.  21
    Information Flow In Logics in the Vicinity of BB.Andrew Tedder - 2021 - Australasian Journal of Logic 18 (1):1-24.
    Situation theory, and channel theory in particular, have been used to provide motivational accounts of the ternary relation semantics of relevant, substructural, and various non-classical logics. Among the constraints imposed by channel-theory, we must posit a certain existence criterion for situations which result from the composites of multiple channels (this is used in modeling information flow). In associative non-classical logics, it is relatively easy to show that a certain such condition is met, but the problem is trickier in non-associative logics. (...)
    Direct download (2 more)  
     
    Export citation  
     
    Bookmark   5 citations  
  3.  38
    Consistent Theories in Inconsistent Logics.Franci Mangraviti & Andrew Tedder - 2023 - Journal of Philosophical Logic 52 (04):1133-1148.
    The relationship between logics with sets of theorems including contradictions (“inconsistent logics”) and theories closed under such logics is investigated. It is noted that if we take “theories” to be defined in terms of deductive closure understood in a way somewhat different from the standard, Tarskian, one, inconsistent logics can have consistent theories. That is, we can find some sets of formulas the closure of which under some inconsistent logic need not contain any contradictions. We prove this in a general (...)
    Direct download (3 more)  
     
    Export citation  
     
    Bookmark   2 citations  
  4.  41
    Incorporating the Relation into the Language?Luis Estrada-González, Alessandro Giordani, Tomasz Jarmużek, Mateusz Klonowski, Igor Sedlár & Andrew Tedder - 2021 - Logic and Logical Philosophy 30 (4):711–739.
    In this paper we discuss whether the relation between formulas in the relating model can be directly introduced into the language of relating logic, and present some stances on that problem. Other questions in the vicinity, such as what kind of functor would be the incorporated relation, or whether the direct incorporation of the relation into the language of relating logic is really needed, will also be addressed.
    Direct download (2 more)  
     
    Export citation  
     
    Bookmark   3 citations  
  5.  33
    Relevant propositional dynamic logic.Andrew Tedder & Marta Bilková - 2022 - Synthese 200 (3):1-42.
    Relevant propositional dynamic logics have been sporadically discussed in the broader context of modal relevant logics, but have not come up for sustained investigation until recently. In this paper, we develop a philosophical motivation for these systems, and present some new results suggested by the proposed motivation. Among these, we’ll show how to adapt some recent work to show that the extensions of relevant logics by the extensional truth constants \ are complete with respect to a natural class of ternary (...)
    No categories
    Direct download (3 more)  
     
    Export citation  
     
    Bookmark   2 citations  
  6.  39
    Neighbourhood Semantics for Modal Relevant Logics.Nicholas Ferenz & Andrew Tedder - 2023 - Journal of Philosophical Logic 52 (1):145-181.
    In this paper, we investigate neighbourhood semantics for modal extensions of relevant logics. In particular, we combine the neighbourhood interpretation of the relevant implication (and related connectives) with a neighbourhood interpretation of modal operators. We prove completeness for a range of systems and investigate the relations between neighbourhood models and relational models, setting out a range of augmentation conditions for the various relations and operations.
    Direct download (3 more)  
     
    Export citation  
     
    Bookmark   2 citations  
  7.  25
    A Note on R-Mingle and the Danger of Safety.Andrew Tedder - 2022 - Australasian Journal of Logic 19 (1).
    Dunn has recently argued that the logic R-Mingle (or RM) is a good, and good enough, choice for many purposes in relevant and paraconsistent logic. This includes an argument that the validity of Safety principle, according to which one may infer an arbitrary instance of the law of excluded middle from an arbitrary contradiction, in RM is not a problem because it doesn’t allow one to infer anything new from a contradiction. In this paper, I argue that while Dunn’s claim (...)
    No categories
    Direct download (2 more)  
     
    Export citation  
     
    Bookmark   2 citations  
  8.  34
    Relevant Consequence Relations: An Invitation.Guillermo Badia, Libor Běhounek, Petr Cintula & Andrew Tedder - forthcoming - Review of Symbolic Logic:1-31.
    We generalize the notion ofconsequence relationstandard in abstract treatments of logic to accommodate intuitions ofrelevance. The guiding idea follows theuse criterion, according to which in order for some premises to have some conclusion(s) as consequence(s), the premises must each beusedin some way to obtain the conclusion(s). This relevance intuition turns out to require not just a failure of monotonicity, but also a move to considering consequence relations as obtaining betweenmultisets. We motivate and state basic definitions of relevant consequence relations, both (...)
    Direct download (2 more)  
     
    Export citation  
     
    Bookmark   1 citation  
  9.  76
    Currying Omnipotence: A Reply to Beall and Cotnoir.Andrew Tedder & Guillermo Badia - 2018 - Thought: A Journal of Philosophy 7 (2):119-121.
    Beall and Cotnoir (2017) argue that theists may accept the claim that God's omnipotence is fully unrestricted if they also adopt a suitable nonclassical logic. Their primary focus is on the infamous Stone problem (i.e., whether God can create a stone too heavy for God to lift). We show how unrestricted omnipotence generates Curry‐like paradoxes. The upshot is that Beall and Cotnoir only provide a solution to one version of the Stone problem, but that unrestricted omnipotence generates other problems which (...)
    Direct download (4 more)  
     
    Export citation  
     
    Bookmark   4 citations  
  10.  40
    Axioms for finite collapse models of arithmetic.Andrew Tedder - 2015 - Review of Symbolic Logic 8 (3):529-539.
    The collapse models of arithmetic are inconsistent, nontrivial models obtained from ℕ and set out in the Logic of Paradox (LP). They are given a general treatment by Priest (Priest, 2000). Finite collapse models are decidable, and thus axiomatizable, because finite. LP, however, is ill-suited to normal axiomatic reasoning, as it invalidates Modus Ponens, and almost all other usual conditional inferences. I set out a logic, A3, first given by Avron (Avron, 1991), and give a first order axiom system for (...)
    Direct download (3 more)  
     
    Export citation  
     
    Bookmark   4 citations  
  11.  11
    Disjunction and Negation in Information Based Semantics.Vít Punčochář & Andrew Tedder - 2021 - In Alexandra Silva, Renata Wassermann & Ruy de Queiroz (eds.), Logic, Language, Information, and Computation: 27th International Workshop, Wollic 2021, Virtual Event, October 5–8, 2021, Proceedings. Springer Verlag. pp. 355-371.
    We investigate an information based generalization of the incompatibility-frame treatment of logics with non-classical negation connectives. Our framework can be viewed as an alternative to the neighbourhood semantics for extensions of lattice logic by various negation connectives, investigated by Hartonas. We set out the basic semantic framework, along with some correspondence results for extensions. We describe three kinds of constructions of canonical models and show that double negation law is not canonical with respect to any of these constructions. We also (...)
    No categories
    Direct download  
     
    Export citation  
     
    Bookmark   1 citation  
  12.  18
    Consistency and Decidability in Some Paraconsistent Arithmetics.Andrew Tedder - 2021 - Australasian Journal of Logic 18 (5):473-502.
    The standard style of argument used to prove that a theory is unde- cidable relies on certain consistency assumptions, usually that some fragment or other is negation consistent. In a non-paraconsistent set- ting, this amounts to an assumption that the theory is non-trivial, but these diverge when theories are couched in paraconsistent logics. Furthermore, there are general methods for constructing inconsistent models of arithmetic from consistent models, and the theories of such inconsistent models seem likely to differ in terms of (...)
    No categories
    Direct download (2 more)  
     
    Export citation  
     
    Bookmark   1 citation  
  13.  95
    No cause for collapse.Dustin Gooßens & Andrew Tedder - 2023 - Asian Journal of Philosophy 2 (2):1-19.
    We investigate a hitherto under-considered avenue of response for the logical pluralist to collapse worries. In particular, we note that standard forms of the collapse arguments seem to require significant order-theoretic assumptions, namely that the collection of admissible logics for the pluralist should be closed under meets and joins. We consider some reasons for rejecting this assumption, noting some prima facie plausible constraints on the class of admissible logics which would lead a pluralist admitting those logics to resist such closure (...)
    Direct download (2 more)  
     
    Export citation  
     
    Bookmark  
  14. Situations, Propositions, and Information States.Andrew Tedder - 2022 - In Katalin Bimbó (ed.), Relevance Logics and other Tools for Reasoning: Essays in Honor of J. Michael Dunn. College Publications. pp. 410-426.
  15.  17
    An Algebraic View of the Mares-Goldblatt Semantics.Andrew Tedder - 2024 - Journal of Philosophical Logic 53 (2):331-349.
    An algebraic characterisation is given of the Mares-Goldblatt semantics for quantified extensions of relevant and modal logics. Some features of this more general semantic framework are investigated, and the relations to some recent work in algebraic semantics for quantified extensions of non-classical logics are considered.
    Direct download (3 more)  
     
    Export citation  
     
    Bookmark  
  16.  20
    Introduction to the special issue ‘Valerie Plumwood’s contributions to Logic’.Andrew Tedder & Guillermo Badia - 2023 - Australasian Journal of Logic 20 (2):95-96.
    This is an introduction to the special issue of the AJL on Val Plumwood's manuscript "False Laws of Logic" and her other work in logic.
    Direct download (2 more)  
     
    Export citation  
     
    Bookmark  
  17.  14
    New Directions in Relevant Logic.Andrew Tedder, Shawn Standefer & Igor Sedlar (eds.) - forthcoming - Springer.
    No categories
    Direct download  
     
    Export citation  
     
    Bookmark  
  18.  59
    How Much Propositional Logic Suffices for Rosser’s Essential Undecidability Theorem?Guillermo Badia, Petr Cintula, Petr Hajek & Andrew Tedder - 2022 - Review of Symbolic Logic 15 (2):487 - 504.
    In this paper we explore the following question: how weak can a logic be for Rosser's essential undecidability result to be provable for a weak arithmetical theory? It is well known that Robinson's Q is essentially undecidable in intuitionistic logic, and P. Hajek proved it in the fuzzy logic BL for Grzegorczyk's variant of Q which interprets the arithmetic operations as non-total non-functional relations. We present a proof of essential undecidability in a much weaker substructural logic and for a much (...)
    Direct download (3 more)  
     
    Export citation  
     
    Bookmark  
  19.  18
    Kapsner Complementation: An Algebraic Take on Kapsner Strong Logics.Andrew Tedder - 2023 - Studia Logica 111 (2):321-352.
    Kapsner strong logics, originally studied in the context of connexive logics, are those in which all formulas of the form \(A\rightarrow \lnot A\) or \(\lnot A\rightarrow A\) are unsatisfiable, and in any model at most one of \(A\rightarrow B, A\rightarrow \lnot B\) is satisfied. In this paper, such logics are studied algebraically by means of algebraic structures in which negation is modeled by an operator \(\lnot \) s.t. any element _a_ is incomparable with \(\lnot a\). A range of properties which (...)
    Direct download (3 more)  
     
    Export citation  
     
    Bookmark  
  20. How Much Propositional Logic Suffices for Rosser's Essential Undecidability Theorem?Guillermo Badia, Petr Cintula, Petr Hajek & Andrew Tedder - forthcoming - Review of Symbolic Logic.
    In this paper we explore the following question: how weak can a logic be for Rosser’s essential undecidability result to be provable for a weak arithmetical theory? It is well known that Robinson’s Q is essentially undecidable in intuitionistic logic, and P. Hájek proved it in the fuzzy logic BL for Grzegorczyk’s variant of Q which interprets the arithmetic operations as nontotal nonfunctional relations. We present a proof of essential undecidability in a much weaker substructural logic and for a much (...)
     
    Export citation  
     
    Bookmark  
  21.  40
    On elimination of quantifiers in some non‐classical mathematical theories.Guillermo Badia & Andrew Tedder - 2018 - Mathematical Logic Quarterly 64 (3):140-154.
    Elimination of quantifiers is shown to fail dramatically for a group of well‐known mathematical theories (classically enjoying the property) against a wide range of relevant logical backgrounds. Furthermore, it is suggested that only by moving to more extensional underlying logics can we get the property back.
    Direct download (2 more)  
     
    Export citation  
     
    Bookmark  
  22.  34
    Correction to: Lambek Calculus with Conjugates.Igor Sedlár & Andrew Tedder - 2020 - Studia Logica 109 (3):471-471.
    We, the authors, would like to thank Guillaume Aucher for informing us of his “Displaying Updates in Logic”, published in the Journal of Logic and Computation, 26:1865-1912.
    Direct download (3 more)  
     
    Export citation  
     
    Bookmark  
  23.  32
    Lambek Calculus with Conjugates.Igor Sedlár & Andrew Tedder - 2020 - Studia Logica 109 (3):447-470.
    We study an expansion of the Distributive Non-associative Lambek Calculus with conjugates of the Lambek product operator and residuals of those conjugates. The resulting logic is well-motivated, under-investigated and difficult to tackle. We prove completeness for some of its fragments and establish that it is decidable. Completeness of the logic is an open problem; some difficulties with applying the usual proof method are discussed.
    Direct download (3 more)  
     
    Export citation  
     
    Bookmark  
  24.  11
    Situated Epistemic Updates.Igor Sedlár & Andrew Tedder - 2021 - In Sujata Ghosh & Thomas Icard (eds.), Logic, Rationality, and Interaction: 8th International Workshop, Lori 2021, Xi’an, China, October 16–18, 2021, Proceedings. Springer Verlag. pp. 192-200.
    One way to model epistemic states of agents more realistically is to represent these states by sets of situations rather than possible worlds. In this paper we discuss representations of epistemic update in terms of situations. After linking epistemic update based on deleting epistemic accessibility arrows with update of situations, we discuss two specific kinds of public epistemic update; monotonic update in intuitionistic dynamic epistemic logic, and non-monotonic update in substructural dynamic epistemic logic. Our investigation is mainly conceptual, but leads (...)
    No categories
    Direct download  
     
    Export citation  
     
    Bookmark  
  25.  39
    On Structural Features of the Implication Fragment of Frege’s Grundgesetze.Andrew Tedder - 2017 - Journal of Philosophical Logic 46 (4):443-456.
    We set out the implication fragment of Frege’s Grundgesetze, clarifying the implication rules and showing that this system extends Absolute Implication, or the implication fragment of Intuitionist logic. We set out a sequent calculus which naturally captures Frege’s implication proofs, and draw particular attention to the Cut-like features of his Hypothetical Syllogism rule.
    Direct download (2 more)  
     
    Export citation  
     
    Bookmark  
  26.  35
    Qua Solution, 0-Qua Has Problems.Andrew Tedder, Grace Paterson & David Ripley - 2020 - Journal of Analytic Theology 8 (1):405-411.
    We present an objection to Beall & Henderson’s recent paper defending a solution to the fundamental problem of conciliar Christology using qua or secundum clauses. We argue that certain claims the acceptance/rejection of which distinguish the Conciliar Christian from others fail to so distinguish on Beall & Henderson’s 0-Qua view. This is because on their 0-Qua account, these claims are either acceptable both to Conciliar Christians as well as those who are not Conciliar Christians or because they are acceptable to (...)
    No categories
    Direct download (3 more)  
     
    Export citation  
     
    Bookmark