Subject	curve
Predicate	has_property
Object	concave
Modality	Modality Occurrences
Polarity	POSITIVE
Plausibility	0.5456
Neighborhood Sigma	0.6026
Local Sigma	0.6030
Example Sentences	Sentence Occurrences Source ppf curves are concave 1 Google Autocomplete curve is concave 2 Google Autocomplete