premise1: Three people with swim caps are swimming in parallel tracks in a large pool, while in the background three other men are walking along the edge of the pool, two in swimsuits, and one in a red shirt and jeans.
premise2: The swimmer in the middle lane appears to be ahead of the swimmers in the lanes on each side of him.
premise3: Three butterfly swimmers in a pool, coming towards the viewer.
premise4: Swimmers having fun in the indoor pool.
premise: Three people with swim caps are swimming in parallel tracks in a large pool, while in the background three other men are walking along the edge of the pool, two in swimsuits, and one in a red shirt and jeans. The swimmer in the middle lane appears to be ahead of the swimmers in the lanes on each side of him. Three butterfly swimmers in a pool, coming towards the viewer. Swimmers having fun in the indoor pool.
hypothesis: Fencers compete.