report definition of field names

[Simon Peyton-Jones]

| Replace:
|      "A datatype declaration may optionally include field labels for
some
|       or all of the components of the type."
| With:
|      "A datatype declaration may optionally include field labels.
Each
|       constructor must use either labelled fields or unlabelled
fields,
|       but different constructors of a datatype may use whichever,
|       independent of the other constructors."

Good point.  This is in the expressions chapter, and it's all explained
quite well in the datatype chapter.  So propose to make a simpler
change:

Replace:
      "A datatype declaration may optionally include field labels for
some
       or all of the components of the type."
 With:
      "A datatype declaration may optionally define field labels (see
Section 4.2.1)."


Simon