Formatting a blank sheet

[Stephen Torri]

I tried to use the blank sheet example found in the documentation. While
I like the fact I see the treble and tab staffs I would like the page to
have at least a 5mm border around the page. I have tried to change the
line-width variable in the paper definition. I see that the line-width =
160mm - 2.0 * 0.4in
                    = 160mm - 2.0 * 10.16mm
                    = 160mm - 20.32mm
                  = 139.68mm

Looking at a ruler this value makes sense given the page. I see this
should give me at least a 0.4 inch border around the page. What I don't
understand is the syntax of the next line that calculates line-width:

  line-width = #(- line-width (* mm  3.000000))

Is this saying that the line-width will be set to 419.04mm?

Stephen

---------------------------

%% Generated by lilypond-book.py
%% Options: [quote,alt=[image of music],indent=0\mm,verbatim]
\include "lilypond-book-preamble.ly"


% ****************************************************************
% Start cut-&-pastable-section 
% ****************************************************************

\paper {
  #(define dump-extents #t)
  
  line-width = 160\mm - 2.0 * 0.4\in
  indent = 0\mm
  force-assignment = #""
  line-width = #(- line-width (* mm  3.000000))
}

\layout {
  
}



% ****************************************************************
% ly snippet:
% ****************************************************************
\sourcefileline 2200
\layout{ indent = #0 }
emptymusic = {
  \repeat unfold 2 % Change this for more lines.
  { s1\break }
  \bar "|."
}
\new Score \with {
  \override TimeSignature #'transparent = ##t
% un-comment this line if desired
%  \override Clef #'transparent = ##t
  defaultBarType = #""
  \remove Bar_number_engraver
} <<

% modify these to get the staves you want
  \new Staff \emptymusic
  \new TabStaff \emptymusic
>>



% ****************************************************************
% end ly snippet
% ****************************************************************