Premise: The 2007 Tennis Masters Cup was a men 's tennis tournament played on indoor hard courts . The Grand Slam tournaments , also called majors , are the four most-important annual tennis events . Roger Federer . He also won the Olympic gold medal in doubles with his compatriot Stan Wawrinka at the 2008 Summer Olympic Games and the Olympic silver medal in singles at the 2012 Summer Olympic Games .
Hypothesis: Roger Federer is a tennis player.
Label: ENTAILMENT