Any superset of an infrequent set is an infrequent set. This is _______.
A. Maximal frequent set.
B. Border set.
C. Upward closure property.
D. Downward closure property.
Answer:C
Any superset of an infrequent set is an infrequent set. This is _______.
A. Maximal frequent set. B. Border set. C. Upward closure property. D. Downward closure property.