Assertion: amphisbaena | /r/CapableOf | leave while the other
Facets:
value: to serve as tail
type: PURPOSE
Source sentences:
text: When it advances, as need for a forward movement impels it, it leaves one end behind to serve as tail, while the other it uses as a head.
text: When it advances, as need for a forward movement impels it, it leaves one end behind to serve as tail, while the other it uses as a head.