[tongzilla]

Sorry for not being clear!

During Follow Through, there can be an instant where there is Zero Accumulator 3, in which case the Right Forearm and the Left arm can both be On Plane at that moment.

With the existence of Accumulator 3, it is not possible for both the Right Forearm and Left Arm to be On Plane at the same time.

10-13-D-2 is the same as 10-13-B-2 in the sense that it includes the situation depicted in 10-13-B-2. They are both trying to show the same thing.

(I have forgotten what the oringal discussion was...!)