A girl wearing a red tank top is sitting on a front porch.
a  girl is outside
A girl outside is not necessarily wearing a red tank top.
exists e1 e2 s1 s2 x1 x2 x3 x4 x5.(on(e2,x5) & n_porch(x5) & a_front(s2) & Theme(s2,x5) & Actor(e2,x1) & v_sit(e2) & Theme(e1,x3) & Actor(e1,x2) & v_wear(e1) & n_top(x3) & of(x3,x4) & n_tank(x4) & a_red(s1) & Theme(s1,x3) & (x1 = x2) & n_girl(x1))
exists s1 x1.(Theme(s1,x1) & a_outside(s1) & n_girl(x1))