Anchor: This was the period when nautical marauders variously called buccaneers, corsairs, privateers, and pirates stalked the shipways and bays of the Caribbean.
Entailed: Pirates often looked for plunder in the Caribbean.
Contradiction: There were never any pirates in the Caribbean.
Contradiction: This is a very easy proposition.  
Contradiction: The instructor was hardly in the room.
Contradiction: Nothing is altered. 
Contradiction: The woman is walking