Two girls drawing sailboats with chalk on the side of concrete.
The children are napping.
They can't be both drawing sailboats and napping.
exists e1 x1 x2 x3 x4 x5 x6.(n_side(x5) & a_topic(x1) & with(e1,x4) & on(x4,x5) & of(x5,x6) & n_concrete(x6) & n_chalk(x4) & Theme(e1,x3) & Actor(e1,x2) & v_draw(e1) & n_sailboat(x3) & (x1 = x2) & n_girl(x1) & card_eq_2(x1))
exists e1 x1.(n_child(x1) & Actor(e1,x1) & v_nap(e1))