A guy typing on a laptop computer.
A man is working on a laptop computer.
The fact that a guy is typing on a laptop doesn't imply he is working.
exists e1 s1 x1 x2 x3.(a_topic(x1) & on(e1,x3) & n_computer(x3) & a_laptop(s1) & Theme(s1,x3) & Actor(e1,x2) & v_type(e1) & (x1 = x2) & n_guy(x1))
exists e1 s1 x1 x2.(on(e1,x2) & n_computer(x2) & a_laptop(s1) & Theme(s1,x2) & Actor(e1,x1) & v_work(e1) & n_man(x1))