Three people on a porch, of which is a little boy who is sitting up straight in his chair.
There are several chairs on the porch.
Only the little boy is said to be sitting in his chair so we cannot assume there are several chairs.
exists p1 x1 x2 x3 x4 x7.(exists e1 s1 s2 x5 x6.((x3 = x5) & r_straight(e1) & in(e1,x7) & a_up(s2) & Manner(e1,s2) & Actor(e1,x6) & v_sit(e1) & (x5 = x6) & n_boy(x5) & a_little(s1) & Theme(s1,x5)) & n_chair(x7) & of(x7,x1) & n_male(x1) & of(x3,x2) & on(x3,x4) & n_porch(x4) & n_people(x3) & card_eq_3(x3) & n_thing(x1) & (x1 = x2))
exists p1 x1 x3.(n_porch(x3) & exists s1 x2.((x1 = x2) & on(x2,x3) & n_chair(x2) & a_several(s1) & Theme(s1,x2)))