Добре дошли в DrRacket, версия 7.0 [3m].
Език: R5RS [потребителски]; memory limit: 128 MB.

> (flatten dl)
((1 ((2 ()) ())) ((((3 ()) (4 ())) ((5 ((6 ()) ())) (() ((7 ()) ())))) (8 ())))
> (flatten dl)
[image] [image] mcar: contract violation
  expected: mpair?
  given: 2
> (flatten dl)
(1 2 3 4 5 6 7 8)
> (deep-reverse dl)
(((() . 8) (((() () . 7)) (() () . 6) . 5) (() . 4) () . 3) (() () . 2) . 1)
> (deep-reverse dl)
[image] [image] mcar: contract violation
  expected: mpair?
  given: 7
> (deep-reverse dl)
(8 ((7) () ((6) 5) (4 (3))) ((2) 1))
> (count-atoms dl)
8
> (flatten dl)
(1 2 3 4 5 6 7 8)
> (deep-reverse dl)
[image] [image] deep-foldr: arity mismatch;
 the expected number of arguments does not match the given number
  expected: 4
  given: 3
  arguments> (deep-reverse dl)
(8 ((7) () ((6) 5) (4 (3))) ((2) 1))
> (count-atoms dl)
[image] [image] foldr: undefined;
 cannot reference an identifier before its definition
> (count-atoms dl)
[image] [image] mcar: contract violation
  expected: mpair?
  given: 1
> (count-atoms dl)
8
> (deep-reverse dl)
(8 ((7) () ((6) 5) (4 (3))) ((2) 1))
> ((lambda l (length l)) 1 2 3 4 5 6)
6
> ((lambda l (length l)) 1 2 3 4)
4
> ((lambda (l) (length l)) 1 2 3 4)
[image] [image] #<procedure>: arity mismatch;
 the expected number of arguments does not match the given number
  expected: 1
  given: 4
  arguments> (append '(1 2 3) '(4 5 6) '(7 8 9) '(10 11))
> (append '(1 2 3) '(4 5 6) '(7 8 9) '(10 11))
(1 2 3 4 5 6 7 8 9 10 11)
> (append '() '(1 2 3) '(4 5 6))
(1 2 3 4 5 6)
> (append '(1 2 3) '(4 5 6))
(1 2 3 4 5 6)
> (append '(1 2 3))
(1 2 3)
> (append)
()
> (eval 2 (interaction-environment))
2
> (define a 2)
> (eval a (interaction-environment))
2
> (eval 'a (interaction-environment))
2
> (evali (list '+ 5 7 'a))
14
> (apply)
[image] [image] mapply: arity mismatch;
 the expected number of arguments does not match the given number
  given: 0
> (apply +)
[image] [image] mapply: arity mismatch;
 the expected number of arguments does not match the given number
  given: 1
  arguments