How to recognize Voice-continuation?

[Thomas Morley]

Hi,

consider the (artificial) code below.
In my naivity I expected that voice-b would be recognized as it works
for voice-a
I.e. the three triggering features (tieWaitForNote, NoteHead.colors
and assigned Lyrics) would work for the second appearance of voice-b.
Any chance to have LilyPond identify the second voice-b as a
continuation of the first?

\version "2.19.17"

lyrI =
\lyricmode { one two three }

lyrII =
\lyricmode { a b c d  e f g h  i j k l  m n o p }

<<
\new Staff
  \relative c' {
    \new Voice = "a"
    \with { \override NoteHead #'color = #green }
    { \set tieWaitForNote = ##t c1~ }

    \new Voice = "b"
    \with { \override NoteHead #'color = #red }
    { \set tieWaitForNote = ##t cis4 d dis e~ }

    \context Voice = "a"
    { d2 c2 }

    \context Voice = "b"
    { f4 e fis g }

    \context Voice = "a"
    { e1 }
  }
\new Lyrics \lyricsto "a" \lyrI
\new Lyrics \lyricsto "b" \lyrII
>>

Cheers,
  Harm