a man walks across the tightrope.
a man walk across a rope
Walk and walks is the same thing  a tightrope is a rope
exists e1 x1 x2.(n_tightrope(x2) & across(e1,x2) & Actor(e1,x1) & v_walk(e1) & n_man(x1))
exists x1 x2 x3.(a_topic(x1) & across(x1,x3) & n_rope(x3) & n_walk(x1) & of(x1,x2) & n_man(x2))