A group of four boys plays with mud in the water and grass.
Children are playing.
Boys are children.
exists e1 x1 x2 x3 x4 x5 x6.(n_water(x5) & with(e1,x3) & subset_of(x6,x3) & n_grass(x6) & subset_of(x4,x3) & in(x4,x5) & n_mud(x4) & Actor(e1,x1) & v_play(e1) & of(x1,x2) & n_boy(x2) & card_eq_4(x2) & n_group(x1))
exists e1 x1.(Actor(e1,x1) & v_play(e1) & n_child(x1))