A group of people rowing a boat.
A group of people are on a boat.
People rowing a boat means they must be on a boat.
exists e1 x1 x2 x3 x4.(a_topic(x1) & of(x1,x2) & Theme(e1,x4) & Actor(e1,x3) & v_row(e1) & n_boat(x4) & (x2 = x3) & n_people(x2) & n_group(x1))
exists p1 x1 x2.(exists x3.(on(x1,x3) & n_boat(x3)) & of(x1,x2) & n_people(x2) & n_group(x1))