An Asian woman, and a black male, walking past the stairs to the subway.
There is a biracial couple walking together.
Just because the Asian woman and black male walk past the stairs does not mean that they are a couple.
exists e1 s1 s2 s3 x1 x2 x3 x4 x5.(n_subway(x5) & n_stair(x4) & a_topic(s1) & to(e1,x5) & past(e1,x4) & Actor(e1,x3) & v_walk(e1) & (s1 = x3) & subset_of(x2,s1) & n_male(x2) & a_black(s3) & Theme(s3,x2) & subset_of(x1,s1) & n_woman(x1) & a_asian(s2) & Theme(s2,x1))
exists p1 x1 e1 s1 s2 x2 x3.((x1 = x2) & a_together(s2) & Manner(e1,s2) & Actor(e1,x3) & v_walk(e1) & (x2 = x3) & n_couple(x2) & a_biracial(s1) & Theme(s1,x2))