mplist_add -

       Copyright (C) 2001 Information-technology Promotion Agency (IPA)
       Copyright (C) 2001-2011 National Institute of Advanced Industrial Science and Technology (AIST)
       Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free
       Documentation License <http://www.gnu.org/licenses/fdl.html>.

Version 1.8.4                                    Mon Sep 25 2023                               mplist_add(3m17n)

       Add a property at the end of a property list. The mplist_add() function appends at the end of property
       list plist a property whose key is key and value is val.  key can be any symbol other than Mnil.

       If key is a managing key, val must be a managed object. In this case, the reference count of val is
       incremented by one.

       mplist_add -

           If the operation was successful, mplist_add() returns a sublist of plist whose first element is the
           just added one. Otherwise, it returns NULL.

MPlist* mplist_add (MPlist * plist, MSymbol key, void * val)