A cyclist is laying on his motorbike while in the air.
A boy surfs.
You cannot be laying and surfing simultaneously.
exists e1 x1 x2 x3.(n_air(x3) & in(e1,x3) & r_while(e1) & on(e1,x2) & n_motorbike(x2) & of(x2,x1) & n_male(x1) & Actor(e1,x1) & v_lay(e1) & n_cyclist(x1))
exists e1 x1.(Actor(e1,x1) & v_surf(e1) & n_boy(x1))