A band is performing on stage.
The band is playing stage while a fan runs onto the stage
A band can perform on a stage without having a fan that runs onto the stage.
exists e1 x1 x2.(on(e1,x2) & n_stage(x2) & Actor(e1,x1) & v_perform(e1) & n_band(x1))
exists e1 p1 x1 x2.(n_band(x1) & exists e2 x3.(onto(e2,x2) & Actor(e2,x3) & v_run(e2) & n_fan(x3)) & n_stage(x2) & n_stage(x2) & while(e1,p1) & Theme(e1,x2) & Actor(e1,x1) & v_play(e1))