A singer performing live in concert.
A concert is going on.
A concert is going on because a singer is performing in a concert.
exists e1 s1 x1 x2 x3.(a_topic(x1) & in(e1,x3) & n_concert(x3) & a_live(s1) & Manner(e1,s1) & Actor(e1,x2) & v_perform(e1) & (x1 = x2) & n_singer(x1))
exists e1 s1 x1.(a_on(s1) & Manner(e1,s1) & Actor(e1,x1) & v_go(e1) & n_concert(x1))