Anchor: For the first period, it is assumed that all controls need to be installed in a 31-month period.
Entailed: All controls are in need of installation within a 31 month timeframe.
Contradiction: The controls need to be installed immediately.
Contradiction: He knew it existed. 
Contradiction: A group of people gathers for a photo.
Contradiction: There isn't much of a shoreline there.
Contradiction: What a quiet place.