A boy sits alone at the bottom of a stone stairway.
Four boys sit together at the bottom of the stone stairway.
There is either one boy or four boys.
exists e1 s1 x1 x2 x3 x4.(n_bottom(x2) & at(e1,x2) & of(x2,x3) & n_stairway(x3) & of(x3,x4) & n_stone(x4) & a_alone(s1) & Manner(e1,s1) & Actor(e1,x1) & v_sit(e1) & n_boy(x1))
exists e1 s1 x1 x2 x3 x4.(n_stairway(x3) & of(x3,x4) & n_stone(x4) & n_bottom(x2) & at(e1,x2) & of(x2,x3) & a_together(s1) & Manner(e1,s1) & Actor(e1,x1) & v_sit(e1) & n_boy(x1) & card_eq_4(x1))