A boy looks on as a baby laughs.
The baby is taking a nap.
The baby can't be taking a nap at the same time as the baby laughs.
exists e1 e2 x1 x2 x3.(r_on(e1) & as(e1,x2) & Actor(e2,x3) & v_laugh(e2) & (x2 = x3) & n_baby(x2) & Actor(e1,x1) & v_look(e1) & n_boy(x1))
exists e1 x1 x2.(n_baby(x1) & Theme(e1,x2) & Actor(e1,x1) & v_take(e1) & n_nap(x2))