A man and a smiling young boy in a float vest are swimming together.
The man and the frowning boy were swimming together.
The boy cannot be smiling and frowning at the same time.
exists e1 e2 p1 s1 x1 x2 x3 x4 x5.(exists s2.(Theme(s2,x1) & a_together(s2)) & Topic(e2,p1) & Actor(e2,x1) & v_swim(e2) & subset_of(x3,x1) & in(x3,x4) & n_vest(x4) & of(x4,x5) & n_float(x5) & n_boy(x3) & a_young(s1) & Theme(s1,x3) & Actor(e1,x3) & v_smile(e1) & subset_of(x2,x1) & n_man(x2))
exists e1 p1 x1 x2 x3 x4.(n_boy(x3) & of(x3,x4) & n_frowning(x4) & n_man(x2) & exists s1.(Theme(s1,x1) & a_together(s1)) & Topic(e1,p1) & Actor(e1,x1) & v_swim(e1) & subset_of(x3,x1) & subset_of(x2,x1))