;; provide an easy hook to tell if we are running with floats or not.
;; define pi and e via math-lib calls. (much less prone to killer typos.)
(defconst pi (* 4 (atan 1)) "The value of Pi (3.1415926...).")
-(defconst e (exp 1) "The value of e (2.7182818...).")
+;; It's too inconvenient to make `e' a constant because it's used as
+;; a temporary variable all the time.
+(defvar e (exp 1) "The value of e (2.7182818...).")
;; Careful when editing this file ... typos here will be hard to spot.
;; (defconst pi 3.14159265358979323846264338327