A group of young adults singing in a choir.
Several people sing a song together.
A group of young adults are several people, and choir implies sing together.
exists e1 s1 x1 x2 x3 x4.(a_topic(x1) & of(x1,x2) & in(e1,x4) & n_choir(x4) & Actor(e1,x3) & v_sing(e1) & (x2 = x3) & n_adult(x2) & a_young(s1) & Theme(s1,x2) & n_group(x1))
exists e1 s1 s2 x1 x2.(a_together(s2) & Manner(e1,s2) & Theme(e1,x2) & Actor(e1,x1) & v_sing(e1) & n_song(x2) & n_people(x1) & a_several(s1) & Theme(s1,x1))