Assertion: ballpoint pen | /r/HasProperty | held upright
Facets:
value: because of a reliance on gravity
type: CAUSE
value: in order to dispense the ink
type: PURPOSE
Source sentences:
text: Because of a reliance on gravity to coat the ball with ink, ballpoint pens must be held upright in order to properly dispense the ink; with the exception of Space Pens, ballpoints cannot be used to write upside down.