A group of people in t-shirts holding yellow signs walk in a street with a castle in the background.
people protest the king
Just  because people are holding signs in front of a castle does not imply they are protesting a king.
exists e1 e2 s1 x1 x2 x3 x4 x5 x6 x7 x8.(n_background(x8) & with(e2,x7) & in(x7,x8) & n_castle(x7) & in(e2,x6) & n_street(x6) & Actor(e2,x1) & v_walk(e2) & of(x1,x2) & Theme(e1,x5) & Actor(e1,x4) & v_hold(e1) & n_sign(x5) & a_yellow(s1) & Theme(s1,x5) & (x2 = x4) & in(x2,x3) & n_t-shirt(x3) & n_people(x2) & n_group(x1))
exists e1 x1 x2.(n_king(x2) & Theme(e1,x2) & Actor(e1,x1) & v_protest(e1) & n_people(x1))