A couple with sunglasses are laying on the beach.
A couple is at the beach and swiming.
Being at the beach does not necessarily mean the couple is swiming.
exists e1 x1 x2 x3.(n_beach(x3) & on(e1,x3) & Actor(e1,x1) & v_lay(e1) & with(x1,x2) & n_sunglass(x2) & n_couple(x1))
exists p1 x1 x2 x3 x4.(n_swiming(x4) & n_beach(x3) & subset_of(x4,x2) & subset_of(x3,x2) & at(x1,x2) & n_couple(x1))