Assertion: porcupine's quill | /r/CapableOf | work their way
Facets:
value: gradually
type: MANNER
value: in deeper
type: OTHER
Source sentences:
text: Quills working their way out: Quills may work themselves out, but most often, they continue to work inward.
text: The quills have barbs and will work their way in deeper if left alone.
text: The barbs on the quills will cause the quills to gradually work their way deeper into an animal's flesh.