“…(M x ψ)(x) = xψ (x), see[14]. Let us remark here that the map E ∓n 2 ,...,n N : B(R) → L(H n 2 ,...,n N ) of the σ -algebra of Borel sets into the lattice of the orthogonal projectors L(H n 2 ,...,n N ) is the spectral measure of the operatorM ∓ H n 2 ...n N , i.e.…”