  Controversy about iteration (repetition) of operators arises again in deontic logic. In some conceptions of obligation, \(OOA\) just amounts to \(OA\). ‘It ought to be that it ought to be’ is treated as a sort of stuttering; the extra ‘ought’s do not add anything new. So axioms are added to guarantee the equivalence of \(OOA\) and \(OA\). The more general iteration policy embodied in \(\mathbf{S5}\) may also be adopted. However, there are conceptions of obligation where distinction between \(OA\) and \(OOA\) is preserved. The idea is that there are genuine differences between the obligations we actually have and the obligations we should adopt. So, for example, ‘it ought to be that it ought to be that \(A\)’ commands adoption of some obligation which may not actually be in place, with the result that \(OOA\) can be true even when \(OA\) is false.