4717: Replace incorrect naming rule in LM (issue 284070043 by address@hidden)

[simon . albrecht]

Reviewers: ,

Message:
I promise to learn how to use git cl &c. correctly :-/
For now, it’s no real problem that it’s an entirely new Rietveld issue,
since I didn’t retain anything from the first approach.

Upon your comments, I replaced the former incorrect wording by a
statement merely expressing a _convention_ of using only alphabetic
characters.  A thorough explanation for the naming rules/conventions in
the NR needs to be done, but that seems to be a major task; I couldn’t
quite find an appropriate place.  IMO it /might/ make sense to make an
entire new chapter about such syntax requirements, either between 3.3
and 3.4 or at 3.3.4.

Description:
4717: Replace incorrect naming rule in LM

This replaces the incorrect rule about naming variables with a
simple reference to the 'alphabetic-only' _convention_.
A thorough explanation in the NR remains to be done.

Please review this at https://codereview.appspot.com/284070043/

Affected files (+1, -2 lines):
  M Documentation/learning/common-notation.itely


Index: Documentation/learning/common-notation.itely
diff --git a/Documentation/learning/common-notation.itely  
b/Documentation/learning/common-notation.itely
index  
9ce651fc02c13e40cff9363c6f5ab49317c934d8..1f68b2b5c7a11db6d3d7d44fda360b4eb21f5e13  
100644
--- a/Documentation/learning/common-notation.itely
+++ b/Documentation/learning/common-notation.itely
@@ -1340,8 +1340,7 @@ cello = \new Staff {
 @end lilypond

 @noindent
-The name of a variable must have alphabetic characters only, no
-numbers, underscores, or dashes.
+By convention, variable names consist of alphabetic characters only.

 Variables must be defined @emph{before} the main music
 expression, but may be used as many times as required anywhere after