Mistake in Chapter 13.2. Editor Configuration - Emacs

[Noam Postavsky]

As seen on https://www.freebsd.org/doc/en_US.ISO8859-1/books/fdp-primer/editor-config-emacs.html;
2015, July 11th.

The config should look like this:

(defun local-sgml-mode-hook ()
  (setq fill-column 70
        indent-tabs-mode nil
        next-line-add-newlines nil
        standard-indent 4
        sgml-indent-data t)
  (auto-fill-mode t)
  (setq sgml-catalog-files '("/usr/local/share/xml/catalog")))
(add-hook 'psgml-mode-hook #'local-psgml-mode-hook)

The "()" after "local-sgml-mode-hook" is especially important,
otherwise the setq form is parsed as the argument list. The lambda in
the add-hook was just redundant.