Chords in LilyPond

[HGoedelmann]

Hallo,

I have great pleasure in writing music sheets with the open source software 
LilyPond 1.2.17. The sequencing software Brahms is not still using LilyPond, 
but 
Noteedit does it in a very good way.
With my actual experience in using LilyPond I notice, that writing 
      \chords {
        a-7.9-.13
      }

gives the chord A7/b9/13/no9 ,

which is not correct.

Is this a thing for later releases, or is there a solution.
Thank you for your reply.


Heinz Gödelmann