An artist painting a river scene, with a man in black shirt watching.
An artists paints a dinning room wall.
Painting a wall  can't be done at the same time as painting a river scene.
all x1 x2.((n_scene(x1) & of(x1,x2) & n_river(x2)) -> exists s1 x3 x4 x5 x6 x7.(a_topic(x3) & with(x3,x5) & in(x5,x6) & n_watching(x6) & of(x6,x7) & n_shirt(x7) & a_black(s1) & Theme(s1,x6) & n_man(x5) & for(x3,x1) & n_painting(x3) & of(x3,x4) & n_artist(x4)))
exists e1 x1 x2 x3 x4.(Theme(e1,x2) & Actor(e1,x1) & v_paint(e1) & n_wall(x2) & of(x2,x4) & n_room(x4) & of(x2,x3) & n_dinning(x3) & n_artist(x1))