I want to know the answer to the following question:
What is frequently the case in quantum mechanics when a pair of alternatives are semantically determinate?
All the background I'm provided with is that "The reason for this is that a quantum disjunction, unlike the case for classical disjunction, can be true even when both of the disjuncts are false and this is, in turn, attributable to the fact that it is frequently the case, in quantum mechanics, that a pair of alternatives are semantically determinate, while each of its members are necessarily indeterminate.". Is that enough to answer the question?