A man and woman are on a gray and white rowboat.
A couple are on a rowboat out on a date.
Not all men and woman are a couple and just because  they are together on a rowboat doesn't mean they are on a date
exists p1 x1 x2 x3.(exists s1 s2 x4.(on(x1,x4) & n_rowboat(x4) & a_white(s2) & Theme(s2,x4) & a_gray(s1) & Theme(s1,x4)) & n_woman(x3) & n_man(x2) & subset_of(x3,x1) & subset_of(x2,x1))
exists p1 s1 x1 x2.(on(p1,x2) & n_date(x2) & a_out(s1) & Manner(p1,s1) & exists x3.(on(x1,x3) & n_rowboat(x3)) & n_couple(x1))