@emph{keys} and @emph{values}. The structure of an alist is:
@example
-#((@var{key1} . @var{value1})
+'((@var{key1} . @var{value1})
(@var{key2} . @var{value2})
(@var{key3} . @var{value3})
@dots{})
can be modified individually without affecting other keys.
For example, to reduce the space between adjacent staves in a
-system, use the @code{staff-staff-spacing} property of the
+staff-group, use the @code{staff-staff-spacing} property of the
@code{StaffGrouper} grob. The property is an alist with four
keys: @code{padding}, @code{space}, @code{minimum-distance}, and
@code{stretchability}. Three of the four keys have initialized
-default values, which are defined (along with all the other grob
-properties) in the file @file{scm/define-grobs.scm}:
+default values; these are listed in the @qq{Backend} section of
+the Internals Reference (see @rinternals{StaffGrouper}):
@example
-(staff-staff-spacing . ((padding . 1)
- (space . 9)
- (minimum-distance . 7)))
+'((space . 9) (minimum-distance . 7) (padding . 1))
@end example
One way to bring the staves closer together is by reducing the
value of the @code{space} key (@code{9}) to match the value of
@code{minimum-distance} (@code{7}). To modify a single key
-individually, use a nested declaration:
+individually, use a @emph{nested declaration}:
@lilypond[quote,verbatim]
% default space between staves
% reduced space between staves
\new PianoStaff \with {
+ % this is the nested declaration
\override StaffGrouper #'staff-staff-spacing #'space = #7
} <<
\new Staff { \clef treble c''1 }
>>
@end lilypond
-Using a nested declaration will update the specified key
-(@code{space} in the above example) without altering any other
-keys already set for the same property.
+Using a nested declaration will update the specified key (such as
+@code{space} in the above example) without altering any other keys
+already set for the same property.
Now suppose we want the staves to be as close as possible without
overlapping. The simplest way to do this is to set all four alist
-keys to zero. In that case, it is not necessary to set each key
-individually with nested declarations. Instead, the property can
-be completely re-defined with one declaration, as an alist:
+keys to zero. However, it is not necessary to enter four nested
+declarations, one for each key. Instead, the property can be
+completely re-defined with one declaration, as an alist:
@lilypond[quote,verbatim]
\new PianoStaff \with {