Similarity and Distance-Their Paths from Crisp to Fuzzy Concepts and an Application in Medical Philosophy

摘要

Similarity and distance are matters of degree for which we can find crisp and fuzzy concepts in the history of mathematics. In this paper we present Lotfi Zadeh's and Karl Menger's crisp concepts before the time of fuzzy sets. Finally we show an application in medical philosophy by Kazem Sadegh-Zadeh that extends into new theoretical research in the field of modern genetics.