Rider riding horse as it jumps over a fence.
The rider is competing for the prize.
riding a horse does not imply competing
exists p1 x1 x2 x3.(a_topic(x1) & exists e1 x4.(over(e1,x4) & n_fence(x4) & Actor(e1,x1) & v_jump(e1)) & n_thing(x1) & as(x1,p1) & n_horse(x1) & of(x1,x3) & n_riding(x3) & (x1 = x2) & ne_nam_rider(x2))
exists e1 x1 x2.(n_prize(x2) & n_rider(x1) & for(e1,x2) & Actor(e1,x1) & v_compete(e1))