People are checking out CDs on an counter.
Some people are shopping.
The people who are shopping are checking out with CDS.
exists e1 s1 x1 x2 x3.(on(e1,x3) & n_counter(x3) & a_out(s1) & Manner(e1,s1) & Theme(e1,x2) & Actor(e1,x1) & v_check(e1) & n_cd(x2) & n_people(x1))
exists p1 x1.(exists x2.((x1 = x2) & n_shopping(x2)) & n_people(x1))