Shape of individual ties in chords

[Richard Shann]

Reading over the documentation on changing the tie shape for ties in
chords I gather that it is not possible to do this at all:

http://www.lilypond.org/doc/v2.18/Documentation/notation/modifying-shapes#modifying-ties-and-slurs
It is not possible to modify shapes of ties or slurs by changing the
control-points property if there are multiple ties or slurs at the same
musical moment – the \tweak command will also not work in this case.
However, the tie-configuration property of TieColumn can be overridden
to set start line and direction as required.

I think the documents should be more up front about that. Saying it is
not possible to do it one way, or another way, and then going on to
describe something else that *is* possible is a bit of weasel-wording.
Unless, that is, there is actually some LilyPond syntax to do this.

Richard