A man on a white surfboard in the ocean riding the waves.
A surfer is showing off his talent to friends on the beach.
A man riding waves on a surfboard is not necessarily showing off to his friends.
exists e1 s1 x1 x2 x3 x4 x5.(n_wave(x5) & n_ocean(x3) & a_topic(x1) & on(x1,x2) & in(x2,x3) & Theme(e1,x5) & Actor(e1,x4) & v_ride(e1) & (x3 = x4) & n_surfboard(x2) & a_white(s1) & Theme(s1,x2) & n_man(x1))
exists e1 s1 x1 x2 x3 x4.(n_beach(x4) & on(e1,x4) & a_off(s1) & Manner(e1,s1) & Theme(e1,x2) & Actor(e1,x1) & v_show(e1) & to(x2,x3) & n_friend(x3) & n_talent(x2) & of(x2,x1) & n_male(x1) & n_surfer(x1))