A referee wearing skates and a helmet is mopping the floor of what looks to be a basketball court.
There was a roller derby tournament.
Just because a referee is wearing skates and a helmet does not mean there was a roller derby tournament.
exists e1 x1 x2 x3 x4 x5 x6.(n_floor(x6) & exists e2 e3 p1 x7.(n_thing(x7) & Theme(e3,x6) & Actor(e3,x1) & v_mop(e3) & of(x6,x7) & Topic(e2,p1) & Actor(e2,x7) & v_look(e2) & exists p2 x8 x9.((x7 = x8) & n_court(x8) & of(x8,x9) & n_basketball(x9))) & subset_of(x5,x1) & n_helmet(x5) & subset_of(x2,x1) & Theme(e1,x4) & Actor(e1,x3) & v_wear(e1) & n_skate(x4) & (x2 = x3) & n_referee(x2))
exists p1 x1 x2 x3 x4.((x1 = x2) & n_tournament(x2) & of(x2,x4) & n_derby(x4) & of(x2,x3) & n_roller(x3))