dinoSpeech

(define sum (make-aggregate + 0))
(sum (list 1 2 3))  ; 6
(define product (make-aggregate * 1))
(product (list 2 3 4))  ; 24

(define sum2 (make-aggregate (lambda (a b) (+ a b)) 0))
(sum2 (list 1 2 3))  ; 6
(define product2 (make-aggregate (lambda (a b) (* a b)) 1))
(product2 (list 2 3 4))  ; 24

dinoSpeech

(define sum (make-aggregate +))
(sum (list 1 2 3))  ; 6
(define product (make-aggregate *))
(product (list 2 3 4))  ; 24