A father helps to ready the line for fishing.
The father is with his son.
Just because a father helps to ready the lines, does not imply he is with his son.
exists e1 e2 s1 x1 x2 x3 x4.(Topic(e1,e2) & Actor(e2,x1) & v_to(e2) & Theme(e1,x3) & Actor(e1,x2) & v_help(e1) & for(x3,x4) & n_fishing(x4) & n_line(x3) & a_ready(s1) & Theme(s1,x3) & n_father(x2) & n_father(x1))
exists p1 x1 x2.(n_son(x2) & of(x2,x1) & n_male(x1) & n_father(x1) & with(x1,x2))