A dog is jumping across an obstacle.
A dog is performing in a competition.
A dog is jumping across and obstacle but the dog isn't necessarily performing in a competition.
exists e1 x1 x2.(across(e1,x2) & n_obstacle(x2) & Actor(e1,x1) & v_jump(e1) & n_dog(x1))
exists e1 x1 x2.(in(e1,x2) & n_competition(x2) & Actor(e1,x1) & v_perform(e1) & n_dog(x1))