A surfer is riding numerous waves.
A surfer is on the water.
Because a surfer is riding numerous waves, the surfer must be on the water.
exists e1 s1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_wave(x2) & a_numerous(s1) & Theme(s1,x2) & n_surfer(x1))
exists p1 x1 x2.(n_water(x2) & on(x1,x2) & n_surfer(x1))