A man and woman fishing at the beach.
A couple are at the beach.
Not every man and woman together are a couple. They could be friends or siblings.
exists s1 x1 x2 x3 x4.(n_beach(x4) & a_topic(s1) & subset_of(x2,s1) & at(x2,x4) & n_fishing(x2) & of(x2,x3) & n_woman(x3) & subset_of(x1,s1) & n_man(x1))
exists p1 x1 x2.(n_beach(x2) & at(x1,x2) & n_couple(x1))