Anchor: Then you cannot have failed to hear the voices inside, especially as they were raised in anger. 
Entailed: You can't have avoided hearing the voices.
Contradiction: I know you didn't hear anything.
Contradiction: I have yet to do so, so sure.
Contradiction: The man is hanging up a balloon.
Contradiction: Pierre van den Berghe said a continuum has no benefits over a black-white dichotomy.
Contradiction: A Nileometer measured the river's height and helped priests with their flood announcements.