(define make-multiplier (lambda (scaling-factor) (lambda (x) (* x scaling-factor)))) (define double (make-multiplier 2)) (define triple (make-multiplier 3)) (define quadruple (make-multiplier 4)) (double 7) ⇒ 14 (triple 12) ⇒ 36 (quadruple 10) ⇒ 40make-multiplier acts like a procedure factory.
Exercise 5.7: very similar (use expt)