@inbook{cintulanoguera2011, title = {A general framework for Mathematical Fuzzy Logic}, author = {Petr Cintula and Carles Noguera}, year = {2011}, editor = {P. Cintula, P. Hájek, C. Noguera (eds)}, publisher = {College Publications}, booktitle = {Handbook of Mathematical Fuzzy Logic}, chapter = {2}, state = {inpress}, acknowledged= {1} }