Fuzzy Logic 2017/18

A semestral course at the Faculty of Informatics, Vienna University of Technology, in the winter term of 2017/18.

Lecturer: PrivDoz. Petr Cintula PhD

Contact: cintula@cs.cas.cz          

 

Credits (3 EC)

There are 25+ exercises in the slides of the corresponding lessons. Students are supposed to choose 15 of them and be able to explain the solutions of the chosen ones at a short exam. For best marks the student will be required to answer additional question for material from lessons 2-5.


 

Aim

The aim of the course is to introduce contemporary Mathematical Fuzzy Logic as a formal tool for reasoning with graded notions. The course gives motivations for the area; introduces several formal systems of fuzzy logic with stress on Lukasiewicz and GödelDummett logics; shows their position in the logical landscape; covers basic and selected advanced mathematical results for both propositional and predicate logic; review recent trends in the development of the area, and showcases their possible applications.

Syllabus

1.     Motivations and historical origins of mathematical fuzzy logic (2 hours) [slides]
 
motivation from computer science, engineering, linguistics, and philosophy; short history of MF; introduction to Łukasiewicz and GödelDummett propositional logics: proof systems and standard semantics

2.     Completeness of propositional Łukasiewicz and Gödel–Dummett logics (6 hours) [slides]
 
completeness with respect to general and linear semantic; standard completeness

3.     Additional properties of propositional Łukasiewicz and Gödel–Dummett logics (3 hours) [slides]
 
functional representation; finite model property; computational complexity
application: fuzzy logic and probability

4.     Predicate Łukasiewicz and Gödel–Dummett logics (3 hours) [slides]
 
syntax, semantics, axiomatizability; completeness; skolemization; witness semantics;
application: fuzzy set theory; formal fuzzy mathematics; counterfactual implications 

5.     The growing family of fuzzy logics (3 hours) [slides]
 
(left-)continuous t-norms and their residua; Mostert--Shield's theorem; Product logic, Esteva and Godo’s MTL; the quest for basic fuzzy logic; logics in richer propositional languages; core semilinear logics as a general theory for fuzzy logics,
application:: fuzzy logic as logic of resources/costs  and logical omniscience paradox

6.     Further lines of research in MFL and open problems (1 hour) [slides]
 
recent development in the core theory of MFL; game theory; model theory; proof theory

 

Prerequisites

Basic knowledge about classical propositional and first-order logic as covered, e.g., in "Theoretische Informatik und Logik".

Study materials

1.     Libor Běhounek, Petr Cintula, and Petr Hájek: Introduction to Mathematical Fuzzy Logic. In Petr Cintula, Carles Noguera, and Petr Hájek (eds). Handbook of Mathematical Fuzzy Logic. Studies in Logic, Mathematical Logic and Foundations, vol. 37 and 38, London, College Publications, 2011.

2.     Cintula, Petr, Fermüller, Christian G. and Noguera, Carles, "Fuzzy Logic", The Stanford Encyclopedia of Philosophy  (Fall 2017 Edition), Edward N. Zalta (ed.), URL = <https://plato.stanford.edu/archives/fall2017/entries/logic-fuzzy/ >.

3.     Petr Cintula, Petr Hájek, and Carles Noguera (eds.). Handbook of Mathematical Fuzzy Logic, College Publications, 2011.

4.     Petr Hájek. Metamathematics of Fuzzy Logic. Kluwer, 1998.