The 'RESULT LIST' has EVERYTHING that the 'LIST 1' does, although, what is selected on 'LIST 1' removes from the 'RESULT LIST' (It's like if you have those Optionals already pre-selected but you have to say which one you DON'T WANT TO, like buying a car.)
And the 'LIST 2' does the Opposite, it has ALL the Optionals, from 1 to 99 we can say, and when selected, it ADDS to the 'RESULT LIST' instead of removing it like 'LIST 1' does.
So, in the example above I'm:
REMOVING the 'Optional 19' and the 'Optional 27' from the 'RESULT LIST' you can see those selections don't appear there AND
ADDING the 'OPTIONAL 2, 12, 14 and 15' from the 'LIST 2' to the 'RESULT LIST'.