Anchor: A man is skateboarding on a road while another man watches from the sidewalk.
Entailed: A man is skateboarding.
Contradiction: A man is doing the worm.
Contradiction: You're both not working and you have this small house. 
Contradiction: Mars in trine to Neptune. 
Contradiction: My siblings and I do not have a green thumb. We avoid gardening.
Contradiction: Dursban gets rid of everything.