(let
  $X6=((bidder & 
  (let
    $X4=(<-1>(open_auction & 
    (let
      $X3=(<-1>(open_auctions & 
      (let
        $X2=(<-1>(site & 
        (let
          $X1=(<-1>(~<-1>T & ~<-2>T & ~<2>T & T) | <-2>$X1)
        in
          $X1)) | <-2>$X2)
      in
        $X2)) | <-2>$X3)
    in
      $X3)) | <-2>$X4)
  in
    $X4) & 
  (let
    $X5=<-2>(bidder | $X5)
  in
    $X5)) | <1>$X6 | <2>$X6)
in
  $X6)