A festival is going on in the streets.
There is a celebration going on
The celebration going on in the streets is a festival.
exists e1 s1 x1 x2.(n_street(x2) & in(e1,x2) & a_on(s1) & Manner(e1,s1) & Actor(e1,x1) & v_go(e1) & n_festival(x1))
exists p1 x1 e1 s1 x2 x3.((x1 = x2) & a_on(s1) & Manner(e1,s1) & Actor(e1,x3) & v_go(e1) & (x2 = x3) & n_celebration(x2))