Anchor: Some people with black belts, or black and red belts, are performing martial arts on a green mat.
Entailed: People performing martial arts on a mat.
Contradiction: A guy with black belts,is selling them for a dollar.
Contradiction: People praying on a green mat.
Contradiction: Some people sit on a mat while an instructor discusses martial arts.
Contradiction: young children attack eachother with belts
Contradiction: Several people, who met at judo class, watched the game together.