A1 boxes out B1, moving B1... Foul on A1?

[bradfordwilkins]

First, make sure I'm clear on that concept (I think I am.)

Second, how much moving till it becomes a foul?

Third: Is the mechanic for it a push?

fourth, Where in the book could I direct a player so they can better understand the rule. A LOT of people think moving someone while boxing them out is LEGAL. Want to teach them the rules before they give the next guy a headache