Assertion: distribution | /r/HasProperty | complementary
Facets:
value: because of three factors
type: CAUSE
Source sentences:
text: The "distribution" (usage according to environments) of the forms an and a is "complementary" because of three factors: (1) an is used if a is not used; (2) a is used if an is not used; (3) both environments together cover every legitimate potential environment for the word.