Anchor: Ashkelon is a site of great antiquity (perhaps 4,000 years old).
Entailed: Ashkelon is a site known for its great antiquity. 
Contradiction: Ashkelon has never been considered to possibly be 4,000 years old.
Contradiction: Three dogs are sleeping on the porch.
Contradiction: We both heard a lightning strike.
Contradiction: Nobody is cooking.
Contradiction: Please come and see me at 11:00 tomorrow.