A man riding a vary tall bike.
A man is on a bike
On a bike implies riding.
exists e2 e1 x1 x2 x3 x4.(r_tall(e2) & Time(e2,x4) & n_bike(x4) & Actor(e2,x1) & v_vary(e2) & Theme(e1,x3) & Actor(e1,x2) & v_ride(e1) & n_a(x3) & (x1 = x2) & n_man(x1))
exists p1 x1.(exists x2.(on(x1,x2) & n_bike(x2)) & n_man(x1))