Two women walk down a busy street together.
The sisters are window shopping.
Two women are not necessarily sisters. Two women walking down a street may not be window shopping. Sisters walking down a street may be window shopping.
exists e1 s1 s2 x1 x2.(a_together(s2) & Manner(e1,s2) & down(e1,x2) & n_street(x2) & a_busy(s1) & Theme(s1,x2) & Actor(e1,x1) & v_walk(e1) & n_woman(x1) & card_eq_2(x1))
exists p1 x1.(n_sister(x1) & exists x2 x3.((x1 = x2) & n_shopping(x2) & of(x2,x3) & n_window(x3)))