摘要： 基本过程：1 (cons n d)2 (car x)3 (cdr x)部分习题：exercise 2.11 (define (make-rat n d)2 (let ((g (gcd n d)))3 (if (negative? (* n d))4 (cons (- (abs (/ n g))) (abs (/ d g)))5 (cons (abs (/ n g)) (abs (/ d g))))))exercise 2.2 1 (define (average x y) 2 (/ (+ x y) 2)) 3 (d... 阅读全文