People congregate on a platform in a river among decorated boats.
People are swimming in the ocean.
People cannot be both swimming and on a platform.
exists e1 s1 x1 x2 x3 x4.(on(e1,x2) & in(x2,x3) & among(x3,x4) & n_boat(x4) & a_decorated(s1) & Theme(s1,x4) & n_river(x3) & n_platform(x2) & Actor(e1,x1) & v_congregate(e1) & n_people(x1))
exists e1 x1 x2.(n_ocean(x2) & in(e1,x2) & Actor(e1,x1) & v_swim(e1) & n_people(x1))