A man rides a horse in a parade.
Someone is leading a parade.
You can not infer someone is leading.
exists e1 x1 x2 x3.(in(e1,x3) & n_parade(x3) & Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_horse(x2) & n_man(x1))
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_lead(e1) & n_parade(x2) & n_person(x1))