 where \(v(A)\) is the set of all generalized eigenvalues of \(A^x\) (i.e., the set of all scalars \(\lambda\) for which there is \(\lambda \in \Phi^x\) such that \(\braket{\phi}{A^x\lambda} = \lambda \braket{\phi}{\lambda}\) for all \(\phi \in \Phi)\).