Assertion: bonobo's relationship | /r/HasProperty | arbitrary and conventional one
Facets:
value: purely
type: DEGREE
value: in human language
type: LOCATION
Source sentences:
text: In human language, the relationship between a word and its referent is a purely arbitrary and conventional one, which must be learned by anyone wishing to speak that language; many words, of course, have no obvious referent at all.