a man walks across the tightrope.
A tightrope walker performs for a crowd.
a man walks across the tightrope does not imply he performs for a crowd.
exists e1 x1 x2.(n_tightrope(x2) & across(e1,x2) & Actor(e1,x1) & v_walk(e1) & n_man(x1))
exists e1 x1 x2 x3.(for(e1,x3) & n_crowd(x3) & Actor(e1,x1) & v_perform(e1) & n_walker(x1) & of(x1,x2) & n_tightrope(x2))