Two large brown dogs are playing in the grass.
The dogs are brothers.
It does not follow that because two dogs are playing that they must somehow be brothers.
exists e1 s1 s2 x1 x2.(n_grass(x2) & in(e1,x2) & Actor(e1,x1) & v_play(e1) & n_dog(x1) & a_brown(s2) & Theme(s2,x1) & a_large(s1) & Theme(s1,x1) & card_eq_2(x1))
exists p1 x1.(n_dog(x1) & exists x2.((x1 = x2) & n_brother(x2)))