Children in swim trunks play in the water on a summer day.
The weather is nice.
They are swimming because the weather is nice.
exists e1 x1 x2 x3 x4 x5 x6.(n_water(x4) & on(e1,x5) & n_day(x5) & of(x5,x6) & n_summer(x6) & in(e1,x4) & Actor(e1,x1) & v_play(e1) & in(x1,x2) & n_trunk(x2) & of(x2,x3) & n_swim(x3) & n_child(x1))
exists s1 x1.(n_weather(x1) & Theme(s1,x1) & a_nice(s1))