Children in canoes floating down a river.
The kids go to school by boat.
The children are floating down a river but aren't necessarily going to school. A canoe does not imply that they are in a boat.
exists e1 s1 x1 x2 x3 x4.(a_topic(x1) & in(x1,x2) & a_down(s1) & Manner(e1,s1) & Theme(e1,x4) & Actor(e1,x3) & v_float(e1) & n_river(x4) & (x2 = x3) & n_canoe(x2) & n_child(x1))
exists e1 x1 x2 x3.(n_kid(x1) & by(e1,x3) & n_boat(x3) & to(e1,x2) & n_school(x2) & Actor(e1,x1) & v_go(e1))