Anchor: Why should there be a sky shell around the planet?
Entailed: Why would there be a shell around the planet?
Contradiction: We need a sky shell. 
Contradiction: That is is exactly the type of player they need.
Contradiction: Freedom can come at a heavy cost, either financial or in loss of human lives.
Contradiction: A man and women are not talking to an elderly women
Contradiction: Two men in a boxing ring.