a lady is wearing all black with a whistle in the middle of rollerskaters.
A lady is in the middle of some rollerskaters.
Rollerskaters make up a portion of some rollerskaters.
exists x1 x5.(n_middle(x5) & all x2.(n_thing(x2) -> exists e1 s1 x3 x4 x6.(Theme(e1,x2) & Actor(e1,x1) & v_wear(e1) & with(x2,x4) & in(x4,x5) & of(x5,x6) & n_rollerskater(x6) & n_whistle(x4) & Theme(s1,x3) & a_black(s1) & (x2 = x3))) & n_lady(x1))
exists p1 x1 x2.(n_middle(x2) & exists x3.(in(x1,x2) & of(x2,x3) & n_rollerskater(x3)) & n_lady(x1))