Items are being sold in the open market by it's vendors.
Items are not being sold.
There can either be items not being sold or items being sold.
exists e1 p1 s1 x1 x2 x3.(n_thing(x2) & n_market(x2) & a_open(s1) & Theme(s1,x2) & Actor(e1,x2) & exists x4.((x3 = x4) & n_vendor(x4)) & (x2 = x3) & in(e1,x2) & Theme(e1,x1) & v_sell(e1) & n_item(x1))
exists x1.(-exists e1.(Theme(e1,x1) & v_sell(e1)) & n_item(x1))