Hello, guys 
The issue is: The body has sleeves with wide coffs. For correct animating (squashing) this coff - when the hand rotating - I putted 4 bones in it: top, side1-inner, bottom, side2-outer.
Now, I need these bones pulled the coff correctly: When I rotate the hand up - top coff’s bone moving to the shoulder. The side bones slightly moving too, BUT the bottom bone has to stay calm. And the opposite way - when I rotate the hand down - the top bone has to do nothing.
The expression I’ve taken from RoyalSky videotutorial (on the screenshot) is good enough for the side bones. But it doesn’t fit for the top and bottom buddies. This two are always moving to the shoulder wherever I rotating the hand - up or down.
Please help me to figure out - what expression do I need to use for the correct moving upper and bottom coff’s bones.
I’m sorry if this question is stupid)) But it’s a big deal for me now) And thank you in advance! I really appreciate your time) 
