There is a man sitting in some kind of truck.
A man is in a truck.
Sitting in truck implies in a truck.
exists p1 x1 e1 x2 x3 x4 x5.((x1 = x2) & in(e1,x4) & of(x4,x5) & n_truck(x5) & n_kind(x4) & Actor(e1,x3) & v_sit(e1) & (x2 = x3) & n_man(x2))
exists p1 x1.(exists x2.(in(x1,x2) & n_truck(x2)) & n_man(x1))