A man in blue coveralls stands on a red train.
The conductor stands in a visible location on the red train.
Just because a man is standing on the train doesn't mean he is visible.
exists e1 s1 s2 x1 x2 x3.(on(e1,x3) & n_train(x3) & a_red(s2) & Theme(s2,x3) & Actor(e1,x1) & v_stand(e1) & in(x1,x2) & n_coverall(x2) & a_blue(s1) & Theme(s1,x2) & n_man(x1))
exists e1 s1 s2 x1 x2 x3.(n_train(x3) & a_red(s2) & Theme(s2,x3) & n_conductor(x1) & in(e1,x2) & on(x2,x3) & n_location(x2) & a_visible(s1) & Theme(s1,x2) & Actor(e1,x1) & v_stand(e1))