People sit on the curb watching an event.
Some people are watching a parade.
Just because people sit on the curb watching an event doesn't necessarily mean the event is a parade.
exists e2 e1 x1 x2 x3.(n_curb(x2) & for(e1,e2) & Theme(e2,x3) & Actor(e2,x1) & v_watch(e2) & n_event(x3) & on(e1,x2) & Actor(e1,x1) & v_sit(e1) & n_people(x1))
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_watch(e1) & n_parade(x2) & n_people(x1))