;; 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 float-pi (* 4 (atan 1)) "The value of Pi (3.1415926...).")
-(defconst pi float-pi "Obsolete since Emacs-23.3. Use `float-pi' instead.")
+(progn
+ ;; Simulate a defconst that doesn't declare the variable dynamically bound.
+ (setq-default pi float-pi)
+ (put 'pi 'variable-documentation
+ "Obsolete since Emacs-23.3. Use `float-pi' instead.")
+ (put 'pi 'risky-local-variable t)
+ (push 'pi current-load-list))
(defconst float-e (exp 1) "The value of e (2.7182818...).")