A group of children are walking down the sidewalk in a line with two adults.
Children are sitting down.
The children can't be walking down and sitting down simultaneously.
exists e1 x1 x2 x3 x4 x5.(n_sidewalk(x3) & down(e1,x3) & in(x3,x4) & with(x4,x5) & n_adult(x5) & card_eq_2(x5) & n_line(x4) & Actor(e1,x1) & v_walk(e1) & of(x1,x2) & n_child(x2) & n_group(x1))
exists e1 s1 x1.(a_down(s1) & Manner(e1,s1) & Actor(e1,x1) & v_sit(e1) & n_child(x1))