premise: Young players engage in the sport of Water polo while others watch.
hypothesis: People are watching and playing a water polo match.
explanation_1: If some are engaged and some watch this means they are watching and playing.
explanation_2: "Young players engage in water polo" is a rephrasing of "people playing water polo". While others watch implies that people are watching.
explanation_3: Young players are people, and playing a water polo match is to engage in the sport.
premise_logic: exists e1 p1 s1 x1 x2 x3 x4.(n_sport(x2) & exists e2 x5.(Actor(e2,x5) & v_watch(e2) & -(x5 = x4) & n_person(x5)) & n_person(x4) & while(e1,p1) & in(e1,x2) & of(x2,x3) & n_polo(x3) & (x3 = x4) & ne_geo_water(x4) & Actor(e1,x1) & v_engage(e1) & n_player(x1) & a_young(s1) & Theme(s1,x1))
hypothesis_logic: exists e1 e2 x1 x2 x3 x4 x5 x6 x7 x8.(Theme(e2,x6) & Actor(e2,x5) & v_play(e2) & n_match(x6) & of(x6,x8) & n_polo(x8) & of(x6,x7) & n_water(x7) & n_people(x5) & Theme(e1,x2) & Actor(e1,x1) & v_watch(e1) & n_match(x2) & of(x2,x4) & n_polo(x4) & of(x2,x3) & n_water(x3) & n_people(x1))