Functionality lost

#print "Computing...";

$get <-
  let $architecture = "i386" in
  let $a =
    ($find_archive
       [
         ["debian"];
         ["stable";"unstable";"testing"];
         ["main";"contrib";"non-free"];
         [ $architecture ]
       ])
   in
   $a;

$lost <-
  $start ->
  $stop ->
  let $architecture = "i386" in
  let $a = ($find_archive [ ["debian"]; ["stable";"unstable";"testing"]; ["main";"contrib";"non-free"]; [$architecture] ]) in
  let $x = ($a $start) in
  let $y = ($a $stop) in
  let $units2 = unit($y) in
  let $sources2 = unit(source($y)) in
  let $replaces2 = replaces($y)
  in
  filter( ($x \ $y),
    $p1 ->
          (not(member($p1, $replaces2)))
      and (not(member(unit($p1), $units2)))
      and (not(member(unit(source($p1)), $sources2))) )

#load "lost.dql"

$lost 2006-01-01 2006-11-01

unit(source($lost 2006-10-01 2006-11-01))

{ apr-util1.0, apr1.0, directfb-0.9-22, gnutls12, kernel-patch-usagi, nvu,
  spca5xx-modules } : set of unit as int set