A person, crouching on a surfboard, is surfing in a body of water.
A person is floating in the water.
crouching and floating are different activities
exists e1 e2 x1 x2 x3 x4 x5.(in(e2,x4) & of(x4,x5) & n_water(x5) & n_body(x4) & Actor(e2,x1) & v_surf(e2) & on(e1,x3) & n_surfboard(x3) & Actor(e1,x2) & v_crouch(e1) & (x1 = x2) & n_person(x1))
exists e1 x1 x2.(n_water(x2) & in(e1,x2) & Actor(e1,x1) & v_float(e1) & n_person(x1))