The surfer rides a wave on a blue surfboard.
the surfer was swimming beside his surfboard
If the surfer rides a wave on his surfboard, he can't be swimming beside his surfboard.
exists e1 s1 x1 x2 x3.(n_surfer(x1) & Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & on(x2,x3) & n_surfboard(x3) & a_blue(s1) & Theme(s1,x3) & n_wave(x2))
exists e1 x1 x2.(n_surfboard(x2) & of(x2,x1) & n_male(x1) & n_surfer(x1) & beside(e1,x2) & Actor(e1,x1) & v_swim(e1))