Fuzzy signed measure
  we will define a fuzzy signed measure on $\sigma$-algebras, as well as positive and negative sets. Herein, we will show that the Fuzzy Hahn Decomposition Theorem, which is a generalization of the classical Hahn Decomposition Theorem, decompose any space X into a positive set A and a negative set B such that A+B=X and the signed measure of $A \wedge B $ is 0. 
Jun Tanaka