A couple of men sit by a large stone slab with mountains in the background.
men sit by a stone slab
The phrase a couple of men can be shortened to just men.
exists e1 s1 x1 x2 x3 x4 x5 x6.(n_background(x6) & by(e1,x3) & with(x3,x5) & in(x5,x6) & n_mountain(x5) & n_slab(x3) & of(x3,x4) & n_stone(x4) & a_large(s1) & Theme(s1,x3) & Actor(e1,x1) & v_sit(e1) & of(x1,x2) & n_man(x2) & n_couple(x1))
exists e1 x1 x2 x3.(by(e1,x2) & n_slab(x2) & of(x2,x3) & n_stone(x3) & Actor(e1,x1) & v_sit(e1) & n_man(x1))