Anchor: It was not necessary to allow for all theoretical courses, but only for the normal orbits.
Entailed: Normal orbits were the only theoretical courses necessitated.
Contradiction: All theoretical courses were allowed except for ones about orbits.
Contradiction: Some people are skateboarding down the sidewalk in a city.
Contradiction: A boy is sitting outside.
Contradiction: A young child is playing with toys.
Contradiction: The discussion was casual.