Anchor: The boat has two large masts.
Entailed: The boat has sails.
Contradiction: The sail boat doesn't need it's two large masts in order to move quickly.
Contradiction: The ostrich has it's head in the ground
Contradiction: The boat is made of sand
Contradiction: The boat is in his living room
Contradiction: There are three masts on this boat, but they are all very small.