“Conceptual graphs (CGs) (Sowa 1976; 1984) and fuzzy logic (Zadeh 1965; 1975a) are two logical formalisms that emphasize the target of natural language, each of which is focused on one of the two mentioned desired features of a logic for handling natural language. Conceptual graphs, based on semantic networks and Peirce's existential graphs, combine the visual advantage of graphical languages and the expressive power of logic.”