\version "2.19.45"
boring = \set Staff.keepAliveInterfaces = #'()
tricky = \unset Staff.keepAliveInterfaces

staffC = {
  \boring \repeat unfold 72 c''4
  \tricky <c'' g''>1
  \boring \repeat unfold 44 c''4
  R1*10
}

staffD = {
  \boring \repeat unfold 80 c'4
  \tricky <c' g'>1
  \boring \repeat unfold 36 c'4
  R1*10
}

\score {
  <<
    \new Staff \with {
      instrumentName = "Continuous"
      shortInstrumentName = "c"
    } { \repeat unfold 200 g'4 }
    \new StaffGroup \with {
      \consists Keep_alive_together_engraver
    } <<
      \new Staff \with {
        keepAliveInterfaces = #'()
        instrumentName = "With group"
        shortInstrumentName = "w"
		    \override VerticalAxisGroup.remove-empty = ##t
		    \override VerticalAxisGroup.remove-first = ##t
        %%% uncomment for 0001-Keep-a-staff-alive-until-it-is-alone-in-the-group.patch
        %\override VerticalAxisGroup.remove-orphan = ##t
        %%% uncomment for 0001-Keep-a-staff-alive-with-multiple-layers.patch
        %\override VerticalAxisGroup.remove-layer = #'(#f) % lives with A and/or B
        %\override VerticalAxisGroup.remove-layer = #'(1) % lives with C and/or D
        %\override VerticalAxisGroup.remove-layer = #'(2) % lives with C+D
        %\override VerticalAxisGroup.remove-layer = #'(#f 1) % lives with A, B, C or D
        %\override VerticalAxisGroup.remove-layer = 1,2 % lives with C, D or C+D
      } { \repeat unfold 200 c''4 }
      \new Staff \with {
        instrumentName = "A"
        shortInstrumentName = "A"
		    \override VerticalAxisGroup.remove-empty = ##t
		    \override VerticalAxisGroup.remove-first = ##t
        \override VerticalAxisGroup.remove-layer = ##f
      } {
        \repeat unfold 20 c'4
        R1*20
        \repeat unfold 20 c'4
        R1*20
      }
      \new Staff \with {
        instrumentName = "B"
        shortInstrumentName = "B"
		    \override VerticalAxisGroup.remove-empty = ##t
		    \override VerticalAxisGroup.remove-first = ##t
        \override VerticalAxisGroup.remove-layer = ##f
      } {
        R1*10
        \repeat unfold 40 c'4
        \repeat unfold 40 c'4
        R1*20
      }
      \new Staff \with {
        instrumentName = "C"
        shortInstrumentName = "C"
		    \override VerticalAxisGroup.remove-empty = ##t
		    \override VerticalAxisGroup.remove-first = ##t
        \override VerticalAxisGroup.remove-layer = 1
      } \staffC
      \new Staff \with {
        instrumentName = "D"
        shortInstrumentName = "D"
		    \override VerticalAxisGroup.remove-empty = ##t
		    \override VerticalAxisGroup.remove-first = ##t
        \override VerticalAxisGroup.remove-layer = 1
      } \staffD
      \new Staff \with {
        instrumentName = "C plus D"
        shortInstrumentName = "C+D"
        %%% TODO: how to remove this staff when both C and D are rests
		    %\override VerticalAxisGroup.remove-empty = ##t
		    %\override VerticalAxisGroup.remove-first = ##t
        \override VerticalAxisGroup.remove-layer = 2
      } << \staffC \\ \staffD >>
    >>
  >>
}