Justification Logic

Develops a new logic paradigm which emphasizes evidence tracking, including theory, connections to other fields, and sample applications.

This book creates a conceptual schema that acts as a correlation between Epistemology and Epistemic Logic. It connects both fields and offers a proper theoretical foundation for the contemporary developments of Epistemic Logic regarding the dynamics of information. It builds a bridge between the view of Awareness Justification Internalism, and a dynamic approach to Awareness Logic. The book starts with an introduction to the main topics in Epistemic Logic and Epistemology and reviews the disconnection between the two fields. It analyses three core notions representing the basic structure of the conceptual schema: “Epistemic Awareness”, “Knowledge” and “Justification”. Next, it presents the Explicit Aware Knowledge (EAK) Schema, using a diagram of three ellipses to illustrate the schema, and a formal model based on a neighbourhood-model structure, that shows one concrete application of the EAK-Schema into a logical structure. The book ends by presenting conclusions and final remarks about the uses and applications of the EAK-Schema. It shows that the most important feature of the schema is that it serves both as a theoretical correlate to the dynamic extensions of Awareness Logic, providing it with a philosophical background, and as an abstract conceptual structure for a re-interpretation of Epistemology.

This book constitutes the refereed proceedings of the International Symposium on Logical Foundations of Computer Science, LFCS 2022, held in Deerfield Beach, FL, USA, in January 2022. The 23 revised full papers were carefully reviewed and selected from 35 submissions. The scope of the Symposium is broad and includes constructive mathematics and type theory; homotopy type theory; logic, automata, and automatic structures; computability and randomness; logical foundations of programming; logical aspects of computational complexity; parameterized complexity; logic programming and constraints; automated deduction and interactive theorem proving; logical methods in protocol and program verification; logical methods in program specification and extraction; domain theory logics; logical foundations of database theory; equational logic and term rewriting; lambda and combinatory calculi; categorical logic and topological semantics; linear logic; epistemic and temporal logics; intelligent and multiple-agent system logics; logics of proof and justification; non-monotonic reasoning; logic in game theory and social software; logic of hybrid systems; distributed system logics; mathematical fuzzy logic; system design logics; other logics in computer science.

Justification logics are closely related to modal logics and can be viewed as a refinement of the latter with machinery for justification manipulation. Justifications are represented directly in the language by terms, which can be interpreted as formal proofs in a deductive system, evidence for knowledge, winning strategy in a game, etc. This more expressive language proved beneficial in both proof theory and epistemology and helped investigate problems ranging from a classical provability semantics for intuitionistic logic to the logical omniscience problem. Justification logic is a new and fast evolving field that offers unexpected new approaches and insights into old problems. Its position at the junction of mathematics, philosophy, and computer science makes it of interest to a wide audience. This book provides a rigorous introduction to justification logic. It covers the basic constructions of justification logic as well as epistemic models and provability semantics. Further it includes chapters on decidability and complexity of justification logics as well as a chapter on self-referentiality. It also contains detailed historic remarks on the subject.

This book constitutes the proceedings of the 9th International Symposium on Foundations of Information and Knowledge Systems, FoIKS 2016, held in Linz, Austria, in March 2016. The 14 revised full papers presented papers were carefully reviewed and selected from 23 submissions. The papers address various topics such as reasoning about beliefs, uncertainty, incompleteness, and inconsistency, inference and problem solving, querying and pattern mining, dealing with knowledge, logics and complexity.

This volume develops a theory of meaning and a semantics for both mathematical and empirical sentences inspired to Chomsky’s internalism, namely to a view of semantics as the study of the relations of language not with external reality but with internal, or mental, reality. In the first part a theoretical notion of justification for a sentence A is defined, by induction on the complexity of A; intuitively, justifications are conceived as cognitive states of a particular kind. The main source of inspiration for this part is Heyting’s explanation of the intuitionistic meaning of logical constants. In the second part the theory is applied to the solution of several foundational problems in the theory of meaning and epistemology, such as Frege’s puzzle, Mates’ puzzle about synonymy, the paradox of analysis, Kripke’s puzzle about belief, the de re/de dicto distinction, the specific/non-specific distinction, Gettier’s problems, the paradox of knowability, and the characterization of truth. On a more general philosophical level, throughout the book the author develops a tight critique of the neo-verificationism of Dummett, Prawitz and Martin-Löf, and defends a mentalist interpretation of intuitionism.