A group of friends on the grass playing a sport.
People playing in a friendly game to determine who pays for pizza.
Just because the people are playing a sport, doesn't mean they are competing to pay for pizza.
exists e1 x1 x2 x3 x4 x5.(n_grass(x3) & a_topic(x1) & Theme(e1,x5) & Actor(e1,x4) & v_play(e1) & n_sport(x5) & (x1 = x4) & on(x1,x3) & of(x1,x2) & n_friend(x2) & n_group(x1))
exists e1 p1 s1 x1 x2 x3 x4.(a_topic(x1) & Topic(e1,p1) & exists e2 e3 x5 x6.(Topic(e2,e3) & for(e3,x6) & n_pizza(x6) & Actor(e3,x5) & v_pay(e3) & n_person(x5) & Actor(e2,x2) & v_determine(e2)) & in(e1,x4) & n_game(x4) & a_friendly(s1) & Theme(s1,x4) & Actor(e1,x3) & v_play(e1) & (x1 = x3) & (x1 = x2) & n_people(x1))