OK, so you don't know what "mutually exclusive" means either.....
I've been saying it over, and over, and over - the definitions overlap on a word, and that word is disbelief.
Imagine for a moment that we're arguing over the definitions of the words hot and cold.
Cold: without heat
Hot: heat
These words have different definitions, but they are related on the presence or absence of heat. This difference in definition makes them mutually exclusive - one has it, the other does not.
You can continue to argue that you have a disbelief while simultaneously having no disbelief - and I'll continue to tell you that those things are mutually exclusive. You cannot have disbelief while not having disbelief - you cannot have heat at the same time as you have no heat.