Two young kids are playing in the grass.
The children are indoors.
If children are playing indoors, they cannot be playing in the grass.  Grass grows outside.
exists e1 s1 x1 x2.(n_grass(x2) & in(e1,x2) & Actor(e1,x1) & v_play(e1) & n_kid(x1) & a_young(s1) & Theme(s1,x1) & card_eq_2(x1))
exists p1 x1.(n_child(x1) & exists x2.((x1 = x2) & n_indoor(x2)))