Men riding skateboards.
There are guys riding on skateboards
Men can be described as guys.
exists s1 x1 x2 x3.(n_skateboard(x1) & a_.(s1) & Theme(s1,x1) & of(x1,x3) & n_riding(x3) & of(x1,x2) & n_man(x2) & a_topic(x1))
exists p1 x1 e1 x2 x3 x4.((x1 = x2) & on(e1,x4) & n_skateboard(x4) & Actor(e1,x3) & v_ride(e1) & (x2 = x3) & n_guy(x2))