A mountain bike rider wearing a helmet rides down a mountain trail with trees and a mountain ridge in the background.
The mountain biker is not wearing a helmet.
One cannot be wearing a helmet and not wearing a helmet at the same time
exists e2 e1 s1 x1 x2 x3 x4 x5 x6 x7 x8 x9 x10 x11 x12.(n_background(x12) & with(e2,x8) & subset_of(x10,x8) & in(x10,x12) & n_ridge(x10) & of(x10,x11) & n_mountain(x11) & subset_of(x9,x8) & n_tree(x9) & a_down(s1) & Manner(e2,s1) & Theme(e2,x6) & Actor(e2,x1) & v_ride(e2) & n_trail(x6) & of(x6,x7) & n_mountain(x7) & Theme(e1,x5) & Actor(e1,x4) & v_wear(e1) & n_helmet(x5) & (x1 = x4) & n_rider(x1) & of(x1,x3) & n_bike(x3) & of(x1,x2) & n_mountain(x2))
exists x1 x2.(n_biker(x1) & of(x1,x2) & n_mountain(x2) & -exists e1 x3.(Theme(e1,x3) & Actor(e1,x1) & v_wear(e1) & n_helmet(x3)))