[Jeff]

Yoda - now I can understand why you describe the right arm's pushing action at PP#1 as a pulling action.

I have always understood pull and push differently. I think of a horse pushing against his harness so that the cart can be pulled by the horse (via the harness). However, I can understand how somebody else can combine these two factual phenomena into a single phenomenon and simply state that the horse is pulling the cart.

Jeff.