lilypond

How to abbreviate 'note with the same note an octave higher, parenthesized' in Lilypond?

Currently I write lilypond code that looks like this: \version "2.14.2" P = #parenthesize \relative c, { \clef bass <c \P c'> <e \P e'> <g \P g'>2 <c, \P c'>4 <d \P d'> <e \P e'>2 } where I repeatedly mean ' this note, together with the same note one octave higher, parenthesized'. I'd like a way to...