A child in red is riding a bicycle.
The boy is riding a bicycle.
A child in red is not a boy.
exists e1 x1 x2 x3.(Theme(e1,x3) & Actor(e1,x1) & v_ride(e1) & n_bicycle(x3) & in(x1,x2) & n_red(x2) & n_child(x1))
exists e1 x1 x2.(n_boy(x1) & Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_bicycle(x2))