Anchor: A group of people riding a yellow roller coaster.
Entailed: A group of people are riding a roller coaster.
Contradiction: A group of people are riding in a car.
Contradiction: People gather in a concert hall.
Contradiction: If they were my kids I would do it.  
Contradiction: The amount a nation is able to invest in domestic capital is capped by the savings of that nation.
Contradiction: The man is swimming..