Two Concepts of Double Prevention

Is double prevention causation? Some say yes and some say no, but the answer is yes and no. Interrupting double prevention, where A prevents B from continuing to prevent something, is causation, while blocking double prevention, where A intervenes before B has begun preventing anything, is not. I present two arguments for this thesis. First, it sorts canonical examples of double prevention correctly. Second, well-known theoretical arguments that double prevention is not causation only show that blocking double prevention is not causation.