Misc GOOPS chapter updates

* doc/ref/goops-tutorial.texi: Update intro text.  Fix `an' typo.

* doc/ref/goops.texi: Update quick start intro text.  Simplify
  example that uses `format'.

doc/ref/goops-tutorial.texi

@@ -30,9 +30,9 @@
 @c Guile
 @c @end macro
 
-This tutorial introduces the @goops{} package.  It was originally
+This section introduces the @goops{} package in more detail.  It was
-written by Erick Gallesio as an appendix for the STk reference manual,
+originally written by Erick Gallesio as an appendix for the STk
-and subsequently adapted to @goops{}.
+reference manual, and subsequently adapted to @goops{}.
 
 The procedures and syntax described in this tutorial are provided by
 Guile modules that may need to be imported before being available.
@@ -109,7 +109,7 @@ example.}  This can be done with the following class definition:
 @end lisp
 
 This binds the variable @code{<my-complex>} to a new class whose
-instances will contain two slots.  These slots are called @code{r} an
+instances will contain two slots.  These slots are called @code{r} and
 @code{i} and will hold the real and imaginary parts of a complex
 number. Note that this class inherits from @code{<number>}, which is a
 predefined class.@footnote{@code{<number>} is the direct superclass of

doc/ref/goops.texi

@@ -40,7 +40,7 @@ meta object protocol, in the spirit of the one defined for CLOS
 @section Quick Start
 
 To give an immediate flavour of what GOOPS can do, here is a very
-quick introduction to its main operations.
+brief introduction to its main operations.
 
 To start using GOOPS, load the @code{(oop goops)} module:
 
@@ -89,8 +89,7 @@ types, Guile falls back to using the normal Scheme @code{+} procedure.
 (use-modules (ice-9 format))
 
 (define-method (write (obj <2D-vector>) port)
-  (display (format #f "<~S, ~S>" (x-component obj) (y-component obj))
+  (format port "<~S, ~S>" (x-component obj) (y-component obj)))
-           port))
 
 (define v (make <2D-vector> #:x 3 #:y 4))