Three boys with no shirts on are sitting on cement steps by the water.
Three boys sit in a classroom
One cannot sit in a classroom and site on cement steps by the water at the same time.
exists x1 x6.(n_water(x6) & -exists e1 s1 x2 x3 x4 x5.(on(e1,x4) & by(x4,x6) & n_step(x4) & of(x4,x5) & n_cement(x5) & Actor(e1,x1) & v_sit(e1) & with(x1,x2) & Theme(s1,x3) & a_on(s1) & (x2 = x3) & n_shirt(x2)) & n_boy(x1) & card_eq_3(x1))
exists e1 x1 x2.(in(e1,x2) & n_classroom(x2) & Actor(e1,x1) & v_sit(e1) & n_boy(x1) & card_eq_3(x1))