A man is lying in the grass.
The man is in the grass.
Lying in the grass and being in the grass are functionally the same phrase.
exists e1 x1 x2.(n_grass(x2) & in(e1,x2) & Actor(e1,x1) & v_lie(e1) & n_man(x1))
exists p1 x1 x2.(n_grass(x2) & n_man(x1) & in(x1,x2))