A man is swimming with a little boy who is wearing a life jacket.
The father is teaching his son to swim.
The man swimming with the boy does not mean that he is his father.
exists e1 e2 s1 x1 x2 x3 x4 x5.(with(e1,x2) & Theme(e2,x4) & Actor(e2,x3) & v_wear(e2) & n_jacket(x4) & of(x4,x5) & n_life(x5) & (x2 = x3) & n_boy(x2) & a_little(s1) & Theme(s1,x2) & Actor(e1,x1) & v_swim(e1) & n_man(x1))
exists e1 p1 x1 x2.(n_son(x2) & of(x2,x1) & n_male(x1) & n_father(x1) & Topic(e1,p1) & exists e2.(Actor(e2,x1) & v_swim(e2)) & Theme(e1,x2) & Actor(e1,x1) & v_teach(e1))