A musician is giving a concert to fans.
there is a riot happening
A concert is not a riot
exists e1 x1 x2 x3.(to(e1,x3) & n_fan(x3) & Theme(e1,x2) & Actor(e1,x1) & v_give(e1) & n_concert(x2) & n_musician(x1))
exists p1 x1 e1 x2 x3.((x1 = x2) & Actor(e1,x3) & v_happen(e1) & (x2 = x3) & n_riot(x2))