Anchor: People are walking up and down a busy city sidewalk.
Entailed: The people are walking on the sidewalk.
Contradiction: The people are walking on the island.
Contradiction: It was a forum that instructed programs on how to fight one another.
Contradiction: Prehistoric sacred structures were often build specifically for special ceremonies, then dismantled after the rituals were complete. 
Contradiction: The infant is a walrus.
Contradiction: We take it home in a plastic container.