A brown dog is biting a black dog.
The black dog bite the brown one first.
Just because the brown dog is biting the black dog doesn't imply that the brown dog is retaliating for a previous bite from the black dog. There is no indication of a previous bite.
exists e1 s1 s2 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_bite(e1) & n_dog(x2) & a_black(s2) & Theme(s2,x2) & n_dog(x1) & a_brown(s1) & Theme(s1,x1))
exists s1 s2 x1 x2 x3.(n_bite(x1) & of(x1,x2) & n_dog(x2) & a_black(s1) & Theme(s1,x1) & a_topic(x1) & n_first(x3) & card_eq_1(x3) & a_brown(s2) & Theme(s2,x3) & (x1 = x3))