The man without a shirt is sitting on a rock by a tree.
And the rock rolled off the hill.
There is either a man sitting on a rock, or a rock rolling of a hill.
exists e1 x1 x2 x3.(n_man(x1) & by(e1,x3) & n_tree(x3) & on(e1,x2) & n_rock(x2) & Actor(e1,x1) & v_sit(e1) & -exists x4.(with(x1,x4) & n_shirt(x4)))
exists e1 s1 x1 x2.(n_hill(x2) & n_rock(x1) & r_and(e1) & a_off(s1) & Manner(e1,s1) & Theme(e1,x2) & Actor(e1,x1) & v_roll(e1))