one of the documented procedures in this installation of the ACS
ad_user_has_permission_p   db   user_id   permission_type   on_what_id   on_which_table
What it does:
Returns true (1) if the specified user has the requested type of permission on the specified row in the specified table; otherwise, returns false (0).
Defined in: /web/philip/tcl/ad-general-permissions.tcl

Source code:

    return [database_to_tcl_string $db "select
 decode(ad_general_permissions.user_has_row_permission_p($user_id, '$permission_type', '$on_what_id', '$on_which_table'), 't', 1, 0)
from dual"]