Step 4:
(CONSTITUENT ((:SYNTACTICALFORM :MCS))
   (AGGREGATION COREDAGGOBJ
      ((CONSTITUENT "Anheben"
         (CONSTITUENT "der"
             (CONSTITUENT "Bauchdecke"))
            (CONSTITUENT "mit"
               (CONSTITUENT "zwei"
         (CONSTITUENT "Backhausklemmen")))))
          (CONSTITUENT "Einführen"))
      (CONSTITUENT "des" (CONSTITUENT "Kameratrokars")))
       (CONSTITUENT "Einbringen"))
   (CONSTITUENT "der"
      (CONSTITUENT "Optik")))))
   :ELLIPSIS-NP T))
The morphosyntacticals expressions have now generated a syntax tree where only one node (Aggregation) is not yet evaluated. This function now examines the three noun phrases and detects that the two latter can be aggregated since the heads of the noun phrases "Einführen" ("Insertion") and "Einbringen" ("Installation") are synonymous. Thus, the head is retained and the attributes ("des Kameratrokars", "der Optik") are submitted to the Enum-function. Together with the first noun phrase the resulting conjunct is then again submitted to Enum.


Step 5
(CONSTITUENT ((:SYNTACTICALFORM :MCS))
   (CONSTITUENT "Anheben"
      (CONSTITUENT "der"
         (CONSTITUENT "Bauchdecke"))
      (CONSTITUENT "mit"
         (CONSTITUENT "zwei"
            (CONSTITUENT "Backhausklemmen")))))
   #\,
    (CONSTITUENT "Einbringen"))
    (CONSTITUENT "des" (CONSTITUENT "Kameratrokars")))
    "sowie"
   (CONSTITUENT "der"
      (CONSTITUENT "Optik"))))

Please note that the original syntax tree has to hold more information than shown above. For the detection of synonymity, for instance, the original lexemes have to be kept along with the inflected forms.

Hopefully it has become clear what Suregen-2 is intended to do.
Still a long way has to be gone, comments are welcome.