Distributive equations of implications based on nilpotent triangular norms
In this paper, we explore the distributive equations of implications, both independently and along with other equations. In detail, we consider three classes of equations. (1) By means of the section of I, we give out the sufficient and necessary conditions of solutions for the distributive equation of implication I(x,T(y,z))=T(I(x,y),(x,z)) based on a nilpotent triangular norm T and an unknown function I, which indicates that there are no continuous solutions satisfying the boundary conditions of implications. Under the assumptions that! is continuous except the vertical section I(0,y), y epsilon [0,1), we get its complete characterizations. (2) We prove that there are no solutions for the functional equations I(x,T(y,z))= T(I(x,y),I(x,z)),I(x,I(y,z))= I(T(x,y),z). (3) We obtain the sufficient and necessary conditions on T and I to be solutions of the functional equations I(x,T(y,z))=T(I(x,y),I(x,z)), I(x,y)= I(N(y),N(x)). (C) 2010 Elsevier Inc. All rights reserved.
distributive equations of implications functional equations fuzzy implications nilpotent t-norms