SICPExercise2.19

2.22
(define (for-each2 proc items)(proc (car items))(if (null? (cdr items))(newline)(for-each2 proc (cdr items))))
2.21
(define (square-list3 items)(define (iter things answer)(if (null? things)answer(iter (cdr things)( append answer (list(square (car things)))))))(iter items ()))2.20
(define (square-list1 items)(if (null? items)()(cons (* (car items) (car items) ) (square-list1 (cdr items)))))
(define (square-list2 items)(map (lambda (x) (* x x)) items ))2.19
(define us-coins (list 50 25 10 5 1))
(define uk-coins (list 100 50 20 10 5 2 1 0.5))(define (cc amount coin-values)(cond ((&＃61; amount 0) 1)((or (