About "/" in the regexp

[Xue Fuqiao]

In (info "(elisp) Auto Major Mode"), there is an example of how to prepend 
several pattern pairs to `auto-mode-alist':

          (setq auto-mode-alist
            (append
             ;; File name (within directory) starts with a dot.
             '(("/\\.[^/]*\\'" . fundamental-mode)
               ;; File name has no dot.
               ("/[^\\./]*\\'" . fundamental-mode)
                ...)
             auto-mode-alist))

I'm confused about the first "/" in the two regular expressions.  Why is there 
a slash character?  Can anybody help?  Thanks.

-- 
Best regards, Xue Fuqiao.
http://www.emacswiki.org/emacs/XueFuqiao