A biker performs before a crowd.
People are eating poop.
People do not eat poop while a biker performs.
exists e1 x1 x2.(before(e1,x2) & n_crowd(x2) & Actor(e1,x1) & v_perform(e1) & n_biker(x1))
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_eat(e1) & n_poop(x2) & n_people(x1))