Petite Chez Scheme Version 9.5
Copyright 1984-2017 Cisco Systems, Inc.

> (define a '(2 3 4))
> a
(2 3 4)
> (define b (cons 1 a))
> (eq? a (cdr b))
#t
> (cdr a)
(3 4)
> (cddr a)
(4)
> (cdddr a)
()
> (cddddr a)
Exception in cddddr: incorrect list structure (2 3 4)
> (cdddddr a)
Exception: variable cdddddr is not bound
> (/ 4 5)
4/5
> /
#<procedure />
> (define /
    (lambda (n m)
      (* n (+ 1 m))))
> (/ 4 5)
24
> (max 4 2 1 7 3)
7
> (mod 19 4)
3
> (max 4)
4
> (max)
Exception: incorrect argument count in call (max)
> (max a)
Exception in max: (2 3 4) is not a real number
> (apply max a)
4
> (if 0 1 2)
1
> (if '() 1 2)
1
> (if #f 1 2)
2
> (if (> 3 4) 1 2)
2
> (< 3 4 6 7)
#t
> (< 3 4 2 7)
#f
> (<)
Exception: incorrect argument count in call (<)
> (define letter-to-number
  (lambda (letter)
    (if (eq? letter 'A)
	4.0
	(if (eq? letter 'B+)
	    3.5
	    3.0))))
> (letter-to-number 'A)
4.0
> (letter-to-number 'B+)
3.5
> (letter-to-number 'B)
3.0
> (define letter-to-number
  (lambda (letter)
    (cond [(eq? letter 'A) 4.0]
	  [(eq? letter 'B+) 3.5]
	  [else 3.0])))
> (letter-to-number 'B)
3.0
> (letter-to-number 'A)
4.0
> (define letter-to-number
  (lambda (letter)
    (case (letter)
      [(A) 4.0]
      [(B+) 3.5]
      [else 3.0])))
> (letter-to-number 'A)
Exception: attempt to apply non-procedure A
> (define letter-to-number
  (lambda (letter)
    (case letter
      [(A) 4.0]
      [(B+) 3.5]
      [else 3.0])))
> (letter-to-number 'A)
4.0
> (letter-to-number 'B+)
3.5
> (letter-to-number 'B)
3.0
>