Anchor: Tuppence nodded at him with the air of one who has established a thorough understanding.
Entailed: Tuppence seemed to understand the situation with him thoroughly. 
Contradiction: Tuppence was confused with him and was obviously not able to understand.
Contradiction: one dog sat alone
Contradiction: There is a man on stage.
Contradiction: The man and dog are dancing.
Contradiction: People are riding rapids.