A boy in speedos, wading through a lake.
A boy rows a canoe on the lake.
A boy cannot be wading through a lake and rowing a canoe at the same time.
exists e1 x1 x2 x3 x4.(a_topic(x1) & in(x1,x2) & through(e1,x4) & n_lake(x4) & Actor(e1,x3) & v_wade(e1) & (x2 = x3) & n_speedo(x2) & n_boy(x1))
exists x4.(n_lake(x4) & all x1.(n_canoe(x1) -> exists x2 x3.(a_topic(x2) & on(x2,x4) & for(x2,x1) & n_row(x2) & of(x2,x3) & n_boy(x3))))