Anchor: Several male players from two rollerskating teams are playing a game in a rink, while the referee stands right near them.
Entailed: Several male players rollerskating.
Contradiction: Several female players skating.
Contradiction: The people are outside in the snow.
Contradiction: I didn't feel well. 
Contradiction: I would perform it maybe once a year but not anymore.
Contradiction: a boy jumps over the wall