need a little scheme help

[Bas Peters <bpeters@xxxxxx>]

I have this piece of code:

(define (*extent*)
  (let ((x
	 (data (select-elements (descendants (if (equal? (gi) "MRCB300")
					      (current-node)
					    (ancestor "MRCB300")))
				'(MRCB300-a))))
	)
     (if (string=?
        (substring x (- (string-length x) 1) (string-length x)) ";")
        (substring x 0 (- (string-length x) 1))x)
     )
  )

It removes the last character if the last character is a semi colon. I
would like to add a few OR statements, like this:

if ... ";" OR ":" OR "."

How can this been done within the code above?

May be I should order a usefull Scheme book.

Thanks to any help,

Regards,

Bas Peters
IDC Publishers


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