A kayak on the river is passing by a wire bridge that joins both banks.
a kayak on the river in the fall
A kayak on the river does not imply it is in the fall.
exists e1 e2 x1 x2 x3 x4 x5 x6.(n_bank(x6) & n_river(x2) & by(e1,x3) & Theme(e2,x6) & Actor(e2,x5) & v_join(e2) & (x3 = x5) & n_bridge(x3) & of(x3,x4) & n_wire(x4) & Actor(e1,x1) & v_pass(e1) & on(x1,x2) & n_kayak(x1))
exists x1 x2 x3.(n_fall(x3) & n_river(x2) & a_topic(x1) & on(x1,x2) & in(x2,x3) & n_kayak(x1))