How to add multiple constraints (none and declined to answer) for multiple choice question

[bwin]

A multiple choice question requires two constraints:

• Not possible to select “None of the above” and any other option
• Not possible to select “Decline to answer” and any other option

For single constraints I would use not(selected(.,‘none_of_the_above’) and count-selected(.) >1) but how to add the second constraint? using AND did not work…