A boy and girl play in water.
A boy and girl are wet.
The boy and girl are wet because they are playing in water.
exists x1 x2 x3 x4.(a_topic(x1) & in(x1,x4) & n_water(x4) & n_play(x1) & of(x1,x3) & n_girl(x3) & of(x1,x2) & n_boy(x2))
exists s1 x1 x2 x3.(Theme(s1,x1) & a_wet(s1) & n_girl(x3) & n_boy(x2) & subset_of(x3,x1) & subset_of(x2,x1))