An informally dressed orchestra is rehearsing in an empty auditorium.
A casually dressed orchestra practicing
The orchestra can be practicing while playing.
exists e2 e1 s1 x1 x2.(in(e2,x2) & n_auditorium(x2) & a_empty(s1) & Theme(s1,x2) & Actor(e2,x1) & v_rehearse(e2) & n_orchestra(x1) & Theme(e1,x1) & v_dress(e1) & r_informally(x1))
exists e1 x1 x2.(a_topic(x1) & n_practicing(x1) & of(x1,x2) & n_orchestra(x2) & Theme(e1,x1) & v_dress(e1) & r_casually(x1))