The surfer is riding a wave with a mountain in the background.
A man is riding a wave with a mountain in the background.
surfer doesn't imply  man
exists e1 x1 x2 x3 x4.(n_background(x4) & n_surfer(x1) & with(e1,x3) & in(x3,x4) & n_mountain(x3) & Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_wave(x2))
exists e1 x1 x2 x3 x4.(n_background(x4) & with(e1,x3) & in(x3,x4) & n_mountain(x3) & Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_wave(x2) & n_man(x1))