End pedal optionally with text.

[Andy Bradford]

Hello,

I'm trying to  accomplish something similar to attached  image where the
sustain pedal ends without showing the line. In ASCII:

Ped. __________________/\

Optionally, it would be nice to follow it with something like:

Ped. __________________/\ con ped.

I've been able to eliminate the  bracket, but somehow have not been able
to get rid of the line:

Ped. __________________/\_____

Using something like:

\version "2.18.2"
\relative c' {
  \set Staff.pedalSustainStyle = #'mixed
  a b c d\sustainOn
  e \once\override Staff.PianoPedalBracket.edge-height = #'(1 . 0) f 
\sustainOff \sustainOn g \sustainOff a
}

I've tried  altering Staff.SustainPedalLineSpanner but clearly  I do not
understand what it is for. Even hiding it has no effect.

Is there some documentation for this that I've missed? Any thoughts?

Thanks,

Andy