;; =====================================
;; Procedures as returned values
;; -------------------------------------
; Setup
;
(setq dx
0.00001) ; -Constant `dx` (defun cube
(x
) (* x x x
)) ; -Definition for `cube`
; OBJECTIVE
; This is how we'd like to write our function.
;
(/ (- (g (+ 'x 'dx)) (g 'x))
'dx))
)
; (OBJECTIVE) USE
; This is how we'd like to use our function.
;
((deriv 'cube) 5)
; > This returns an error: no function definition nil.