An Examination of Counterexamples in Proofs and Refutations

Dans son influent Proofs and Refutations (Preuves et Réfutations), Lakatos introduit les méthodes de preuves et de réfutations en discutant l’histoire et le développement de la formule V — E+F = 2 d’Euler pour les polyèdres en 3 dimensions. Lakatos croyait, en effet, que l’histoire du polyèdre présentait un bon exemple pour sa philosophie et sa méthodologie des mathématiques, incluant la géométrie. Le présent travail met l’accent sur les propriétés mathématiques et topologiques qui sont incorporées dans l’approche méthodologique de Lakatos. Pour chaque exemple et contre-exemple utilisé par Lakatos, nous présenterons brièvement sa contrepartie topologique, ce qui nous permettra de présenter les fondations et les motivations mathématiques derrière sa philosophie de la méthodologie des mathématiques et finalement, par ce fait même, nous développerons certaines intuitions sur le fonctionnement de ses notions d’heuristique négative et d’heuristique positive.Abstract: Lakatos’s seminal work Proofs and Refutations introduced the methods of proofs and refutations by discussing the history and methodological development of Euler’s formula V — E+F = 2 for three dimensional polyhedra. Lakatos considered the history of polyhedra illustrating a good example for his philosophy and methodology of mathematics and geometry. In this study, we focus on the mathematical and topological properties which play a role in Lakatos’s methodological approach. For each example and counterexample given by Lakatos, we briefly outline its topological counterpart. We thus present the mathematical background and basis of Lakatos’s philosophy of mathematical methodology in the case of Euler’s formula, and thereby develop some intuitions about the function of his notions of positive and negative heuristics

Applications of Game Theory and Epistemic Logic to Fact-Checking

In this paper, we present a game theoretical and an epistemic logical approach to fact-checking. Game theory is the study of strategic reasoning whereas epistemic logic is the formal study of reasoning about and with knowledge. Fact-checking is strategic because the process involves more than one agent. It is epistemic as the process is all about verifying the correctness of one or more pieces of information – hence checking whether it is indeed “knowledge”. We discuss a variety of typical fact-checking scenarios and present game theoretical and epistemic logical analysis for them

Game theoretical semantics for some non-classical logics

Paraconsistent logics are the formal systems in which absurdities do not trivialise the logic. In this paper, we give Hintikka-style game theoretical semantics for a variety of paraconsistent and non-classical logics. For this purpose, we consider Priest’s Logic of Paradox, Dunn’s First-Degree Entailment, Routleys’ Relevant Logics, McCall’s Connexive Logic and Belnap’s four-valued logic. We also present a game theoretical characterisation of a translation between Logic of Paradox/Kleene’s K3 and S5. We underline how non-classical logics require different verification games and prove the correctness theorems of their respective game theoretical semantics. This allows us to observe that paraconsistent logics break the classical bidirectional connection between winning strategies and truth values

A history based logic for dynamic preference updates

History based models suggest a process-based approach to epistemic and temporal reasoning. In this work, we introduce preferences to history based models. Motivated by game theoretical observations, we discuss how preferences can dynamically be updated in history based models. Following, we consider arrow update logic and event calculus, and give history based models for these logics. This allows us to relate dynamic logics of history based models to a broader framework

An Examination of Counterexamples in Proofs and Refutations

Lakatos’s seminal work Proofs and Refutations introduced the methods of proofs and refutations by discussing the history and methodological development of Euler’s formula V — E+F = 2 for three dimensional polyhedra. Lakatos considered the history of polyhedra illustrating a good example for his philosophy and methodology of mathematics and geometry. In this study, we focus on the mathematical and topological properties which play a role in Lakatos’s methodological approach. For each example and counterexample given by Lakatos, we briefly outline its topological counterpart. We thus present the mathematical background and basis of Lakatos’s philosophy of mathematical methodology in the case of Euler’s formula, and thereby develop some intuitions about the function of his notions of positive and negative heuristics