Dear Tutor, I am a little confused about when to move a "no" or negative indicator to the left in order to apply the "negate the necessary" rule. For example, I understand that " No Cats are Dogs can be diagrammed as such Cat-->/Dog Or Dog-->/Cat. However, what if there is a No on both sides? For example, Prep Test 111 Section 3 Question 18 Answer Choice: (B) reads "No people who understand their musical roots will be in the audience if the audience will not be treated to a good show." I almost diagrammed this by moving the "no" in the sufficient condition to the necessary condition, which would have made B correct. So, if there is a "no" or negative indicator on both sides, it is best to leave it be?