Three little girls are sitting on the grass.
The three girls are sitting.
' sitting on the grass. ' is a rephrasing of  ' sitting.'
exists e1 s1 x1 x2.(n_grass(x2) & on(e1,x2) & Actor(e1,x1) & v_sit(e1) & n_girl(x1) & a_little(s1) & Theme(s1,x1) & card_eq_3(x1))
exists e1 x1.(n_girl(x1) & card_eq_3(x1) & Actor(e1,x1) & v_sit(e1))