All possible involutions in fuzzy set theory are completely described. Any involution is a composition of a symmetry on a universe of fuzzy sets and an involution on a truth set.
@article{urn:eudml:doc:38823, title = {Involutions in fuzzy set theory.}, journal = {Stochastica}, volume = {4}, year = {1980}, pages = {227-231}, zbl = {0466.03023}, mrnumber = {MR0599137}, language = {en}, url = {http://dml.mathdoc.fr/item/urn:eudml:doc:38823} }
Ovchinnikov, Sergei V. Involutions in fuzzy set theory.. Stochastica, Tome 4 (1980) pp. 227-231. http://gdmltest.u-ga.fr/item/urn:eudml:doc:38823/