Anchor: A skateboarder does an ollie off a black ramp near a colorfully painted building.
Entailed: A person does a trick on a skateboard.
Contradiction: A windsurfer dives off his board into the river.
Contradiction: Politicians are shunned for becoming liberal. 
Contradiction: Not everyone like poems that are clear about their meaning.
Contradiction: The rule is very complex suggests to check it out neither from a technical or value oriented perspective.
Contradiction: The differences in slopes and blocks reflect population differences.