Assertion: sphere's surface | /r/CapableOf | rotate one of them
Facets:
value: essentially
type: DEGREE
value: to become
type: PURPOSE
Source sentences:
text: The heart of the proof of the "doubling the ball" form of the paradox presented below is the remarkable fact that by a Euclidean isometry (and renaming of elements), one can divide a certain set (essentially, the surface of a unit sphere) into four parts, then rotate one of them to become itself plus two of the other parts.