Assertion: node's sibling | /r/HasAspect | key
Facets:
Source sentences:
text: If the right sibling has keys, then keys are redistributed between the two sibling nodes as evenly as possible.
text: If a sibling on either side of this node is a 3-node or a 4-node (thus having more than 1 key), perform a rotation with that sibling: The key from the other sibling closest to this node moves up to the parent key that overlooks the two nodes.