the young children are petting a piglet
The young children are petting a horse.
The animal in the petting process cannot be both a piglet and a horse.
exists e1 s1 x1 x2.(n_child(x1) & a_young(s1) & Theme(s1,x1) & Theme(e1,x2) & Actor(e1,x1) & v_pet(e1) & n_piglet(x2))
exists e1 s1 x1 x2.(n_child(x1) & a_young(s1) & Theme(s1,x1) & Theme(e1,x2) & Actor(e1,x1) & v_pet(e1) & n_horse(x2))