\version "2.13.0"

\layout {
    % define Pedals context
    \context {
      \type "Engraver_group"
      \name Pedals
      \consists "Output_property_engraver"
      \consists "Piano_pedal_engraver"
      \consists "Script_engraver"
      \consists "Skip_event_swallow_translator"
      \consists "Axis_group_engraver"

      pedalSustainStrings = #'("Ped." "*Ped." "*")
      pedalUnaCordaStrings = #'("una corda" "" "tre corde")
      \override VerticalAxisGroup #'minimum-Y-extent = #'(-1 . 1)
      pedalSustainStyle = #'bracket
    }
    % modify PianoStaff context to accept Pedals context
    \context {
      \PianoStaff
      \accepts Pedals
    }
  }

susOn = \sustainOn
susOff = \sustainOff

\new PianoStaff <<
    \new Staff {
      c'4 c' c' c'
    }
    \new Staff {
      \times 4/6 { c'4 c' c' c' c' c' }
    }
    \new Pedals {
      s4\susOn s\susOff\susOn s\susOff\susOn s\susOff\susOn
    }
>>