Does the definition of "mutually exclusive" include the case where neither A nor B happen?
I ask this because I remember in logic, "xor" has to be A or B and doesn't include the case where neither A nor B happen.
Here is an example that might help explain what I want to ask.
A: seeing Superman
B: seeing Clark Kent
We can only see either Superman or Clark Kent at a time, and never see them both, and we see neither of them sometimes.
In this case, can we say A and B are mutually exclusive?