Anchor: During fiscal year 1999, GAO made substantial contributions to help the Congress and the executive branch agencies improve government programs and services.
Entailed: GAO made contributions to help Congress improve their functioning.
Contradiction: GAO didn't aim to help Congress at all.
Contradiction: A dog is eating a frog in a creek.
Contradiction: People are looking at food.
Contradiction: I was drowning. 
Contradiction: Death and life insurance are not something one usually looks for.