Anchor: A young couple kiss while a crowd mills in the background on a sunny day.
Entailed: Some people are standing outside.
Contradiction: A young couple are swimming.
Contradiction: He did not know where exactly the station was, so he did not go back there.
Contradiction: A man is walking his dog.
Contradiction: A group of men were drinking at a bar.
Contradiction: I doubt this approach has been followed well enough to be called a general rule.