a man walks across the tightrope.
A man rides his bike down a bike ramp.
If a man walks across a tightrope he cannot be riding his bike down a bike ramp.
exists e1 x1 x2.(n_tightrope(x2) & across(e1,x2) & Actor(e1,x1) & v_walk(e1) & n_man(x1))
exists e1 x1 x2 x3.(Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & down(x2,x3) & n_ramp(x3) & of(x3,x2) & n_bike(x2) & n_bike(x2) & of(x2,x1) & n_male(x1) & n_man(x1))