Premium
Fuzzy implication can be arbitrarily complicated: A theorem
Author(s) -
Fernandez Francisco G.,
Kreinovich Vladik
Publication year - 1998
Publication title -
international journal of intelligent systems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.291
H-Index - 87
eISSN - 1098-111X
pISSN - 0884-8173
DOI - 10.1002/(sici)1098-111x(199805)13:5<445::aid-int5>3.0.co;2-m
Subject(s) - computer science , fuzzy logic , calculus (dental) , algebra over a field , mathematics , discrete mathematics , artificial intelligence , pure mathematics , medicine , dentistry
In fuzzy logic, there are several methods of representing implication in terms of &, ∨, and ¬; in particular, explicit representations define a class of S implications, implicit representations define a class of R implications. Some reasonable implication operations have been proposed, such as Yager's a b , that are difficult to represent as S or R implications. For such operations, a new class of representations has recently been proposed, called A implications, for which the relationship between implications and the basic operations &, ∨, and ¬ is even more complicated. A natural question is: Is this complexity really necessary? In other words, is it true that A operations cannot be described as S or R operations, or they can, but we simply have not found these representations? In this paper we show that yes, the complexity is necessary, because there are operations that cannot be represented in a simpler form. © 1998 John Wiley & Sons, Inc.