Similarity in hierarchical fuzzy rule-base systems

Deals with issues related to fuzzy interpolation and hierarchical fuzzy rule bases, from the point of view of similarity between rule antecedents and observations. The existing distance-based similarities sometimes exhibit strange properties, which make them inadequate for the selection of interpolating fuzzy rules, for instance. In the paper, similarity of two fuzzy sets is expressed as a crisp value, rather then based on a fuzzy distance. This leads to easier rule selection, but also to some modification of the interpolation methods