One of the fundamental interpretive problems of quantum theory arises from the fact that from any two or more states for a system one can create another state, their superposition (mathematically, a linear combination). Let s and be possible states for a system, corresponding to two different values, k and respectively, for the observable, O. (That is, they are mutually orthogonal eigenstates of O.) Their superposition, which is another possible state for the system, is denoted by s + . According to the standard interpretation of quantum theory, a system in the state s + does not have the value k for O, nor the value for O, nor neither, but if O is measured on the system, the system will be found to have either the value of k or the value of for O.