Assertion: mouse's ball | /r/AtLocation | contact
Facets:
value: with mousepad
type: OTHER
value: with the desk
type: OTHER
value: with two small shafts
type: OTHER
Source sentences:
text: The conventional roller-ball mouse uses a ball to create this action: the ball is in contact with two small shafts that are set at right angles to each other.
text: Mice used the same basic system for determining motion, but had the problem that the ball was in contact with the desk or mousepad.