#lang racket (define (my-map f a-list) (if (null? a-list) '() (cons (f (car a-list)) (my-map f (cdr a-list))))) (define (co-map f a-list) (define (co-helper in-list out-list) (if (null? in-list) out-list (co-helper (cdr in-list) (append out-list (list (f (car in-list))))))) (co-helper a-list '())) (provide my-map co-map)