On the Sum of Observables in Product MV Algebras

As an alternative to quantum logics MV algebras have been suggested2,20. In a quite general class of MV algebras there have been constructed sum of any two observables10,14,20. Recently the notion of product MV algebra has been introduced4,5,12,17. In any weakly σ-distributive product MV algebra the joint observable of any observables can be constructed and on the base also the sum of any observables. In this paper we show that the two concepts of constructing of the sum are equivalent.