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shirok/gist:1187459

Created September 1, 2011 22:25
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gistfile1.lisp
(defun arabic->roman (n) (if (< 0 n 4000) (format nil "~@R" n) (error "oob")))
(let ((tab (loop for n from 1 to 3999 collect `(,(format nil "~@R" n) . ,n))))
(defun roman->arabic (r) (or (cdr (assoc r tab :test #'equalp)) (error "huh?"))))
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