Publisher's Synopsis
25 years ago a new paradigm emerged in systems science, which affected thinking about systems in a fundamental way. This paradigm is based upon the notion of a fuzzy set, a notion that is very simple and, yet, its implications are profound. In general, a fuzzy set is a set whose boundary is not sharp. That is, the membership in a fuzzy set is a matter of degree, which is characterized by an appropriate membership grade function.;This special issue of the "International Journal of General Systems" focuses primarily on the notion of fuzzy systems, with a mixture of overviews and new contributions.