A boy climbing a mountain.
He is ice skating down the mountain
Climbing is not ice skating.
exists e1 x1 x2 x3.(a_topic(x1) & Theme(e1,x3) & Actor(e1,x2) & v_climb(e1) & n_mountain(x3) & (x1 = x2) & n_boy(x1))
exists p1 x1 x4.(n_mountain(x4) & n_male(x1) & exists e1 x2 x3.((x1 = x2) & down(e1,x4) & Actor(e1,x3) & v_skate(e1) & (x2 = x3) & n_ice(x2)))