This is the 5rst one of three articles that are intended to be published consecutively in this journal. Together they constitute a three-part work on the uni5ed subject of fuzzy T -neighbourhood spaces and their fuzzy T -proximities, where T stands for any continuous triangular norm. These new notions generalize, to arbitrary T , corresponding ones due to Artico, H8 ohle, Lowen and Moresco. In ...

In this state-of-the-art paper, important advances that have been made during the past five years for both general and interval type-2 fuzzy sets and systems are described. Interest in type-2 subjects is worldwide and touches on a broad range of applications and many interesting theoretical topics. The main focus of this paper is on the theoretical topics, with descriptions of what they are, wh...