Man in a helmet riding a dirt bike covered with mud.
A man is traveling on a bike.
traveling is another way to say riding.
exists e1 e2 x1 x2 x3 x4 x5 x6.(with(e2,x6) & n_mud(x6) & Theme(e2,x1) & v_cover(e2) & in(x1,x2) & Theme(e1,x4) & Actor(e1,x3) & v_ride(e1) & n_bike(x4) & of(x4,x5) & n_dirt(x5) & (x2 = x3) & n_helmet(x2) & n_man(x1))
exists e1 x1 x2.(on(e1,x2) & n_bike(x2) & Actor(e1,x1) & v_travel(e1) & n_man(x1))