ALTER FUNCTION <function-name> ++-> COMMENT IS +-> '<string>' -------+++-+->
                                 ||              +------- / <----------+|| |
                                 |+-> COMPILE --------------------------+| |
                                 |+-> NAME <external-body-name> ---------+ |
                                 |+-> external-location-clause ----------+ |
                                 |+-> LANGUAGE language-name ------------+ |
                                 |+-> notify-clause ---------------------+ |
                                 |+-> RETURNS NULL ON NULL INPUT --------+ |
                                 |+-> CALLED ON NULL INPUT --------------+ |
                                 |+-> bind-site-clause ------------------+ |
                                 |+-> bind-scope-clause -----------------+ |
                                 |+-+--------+--+-------------------+----+ |
                                 || +-> NOT -+  +-> VARIANT --------+    | |
                                 ||             +-> DETERMINISTIC --+    | |
                                 |+> RENAME TO <new-function-name> ------+ |
                                 +--------------<--------------------------+

  external-location-clause =

  ---+--> DEFAULT LOCATION ------------+-------------------------+
     +--> LOCATION '<image-location>' -+                         |
   +-------------------------------<-----------------------------+
   +-+----------------------------->--------------------------+-->
     +--> WITH --+-> ALL -----+--> LOGICAL_NAME TRANSLATION --+
                 +-> SYSTEM --+

  notify-clause =

  -> NOTIFY notify-entry-name --> ON -+-+-> BIND ---------+-+->
                                      | +-> CONNECT ------+ |
                                      | +-> TRANSACTION --+ |
                                      +--------- , <--------+

  bind-site-clause =

  --> BIND ON --+--> CLIENT --+--> SITE --->
                +--> SERVER --+

  bind-scope-clause =

  ---> BIND SCOPE --+-> CONNECT ------+-->
                    +-> TRANSACTION --+