@book { 4412, title = {Understanding Vagueness. Logical, Philosophical, and Linguistic Perspectives}, series = {Studies in Logic}, editor = {Dov Gabbay}, number = {36}, year = {2011}, pages = {425}, publisher = {College Publications}, edition = {Petr Cintula, Christian G. Fermüller, Llu\'{\i}s Godo and Petr H\'ajek}, ISBN = {978-1-84890-037-0}, author = {Petr Cintula and Christian G. Fermüller and Llu\'{\i}s Godo and Petr H\'ajek} }