Some remarks on the distributive equation of fuzzy implication and the contrapositive symmetry for continuous, Archimedean t-norms

In this short article we present corrections of some results presented in Baczyński (2010) [6] and Qin and Yang (2010) [13] which are connected with the distributive equation I(x,T1(y,z))=T2(I(x,y),I(x,z)) and the contrapositive symmetry I(x,y)=I(N(y),N(x)) when T1, T2 are continuous t-norms, N is a strong negation and I an unknown binary function, in particular fuzzy implication.