Anchor: Snowboarder attempting to perform a trick in midair.
Entailed: A snowboarder is performing a trick.
Contradiction: A snowboarder is not performing a trick.
Contradiction: This immense hoard of art works was collected by force by one tyrant in the 7th century.
Contradiction: The workers are involve in an activity.
Contradiction: A train operator is alone on the subway.
Contradiction: Some people are outside on bikes.