Anchor: They have co-presidents and you can have co-maids of honor.
Entailed: There are co-presidents and co-maids of honor.
Contradiction: There aren't any co-presidents.
Contradiction: A group of kids is sitting at the bottom of a ski hill
Contradiction: The Russian moaned distrustfully, "If you blast me, you'll hang."
Contradiction: I didn't go to college.
Contradiction: A conductor of train is on work.