Anchor: A group of boys watch a skateboarder jump a distant staircase.
Entailed: Someone rides a skateboard.
Contradiction: Only rollerbladers are out.
Contradiction: Liam Neeson was not involved in the new Broadway play by David hare.
Contradiction: Labs are really nice dogs, my neighbor has some. 
Contradiction: Ducks are chasing a rowdy group of children away from the zoo
Contradiction: A person is sitting inside with a drink looking out.