A small boy is sitting on a stack of tires.
A small boy is sitting on a stack of tires while his father repairs a car.
No mention of a father who repairs a car.
exists e1 s1 x1 x2 x3.(on(e1,x2) & of(x2,x3) & n_tire(x3) & n_stack(x2) & Actor(e1,x1) & v_sit(e1) & n_boy(x1) & a_small(s1) & Theme(s1,x1))
exists e1 s1 x1 x2 x3 x5 x6.(all x4.(n_car(x4) -> (while(e1,x5) & for(x5,x4))) & n_repair(x5) & of(x5,x6) & n_father(x6) & of(x5,x1) & n_male(x1) & on(e1,x2) & of(x2,x3) & n_tire(x3) & n_stack(x2) & Actor(e1,x1) & v_sit(e1) & n_boy(x1) & a_small(s1) & Theme(s1,x1))