> (contour 3 4)
#<procedure>
> ((contour 3 5) 7 11)
61
> (contour 3 4)
#<procedure>
> '((1 2) (3 4) (5 6))

> (1sts '((1 2) (3 4) (5 6)))
'(1 3 5)
> (map car '((1 2) (3 4) (5 6)))
'(1 3 5)
> (map cadr '((1 2) (3 4) (5 6)))
'(2 4 6)
> (map +  '(1 2 3))
'(1 2 3)
> (map (lambda (x) (+ x 1)) '(1 2 3))
'(2 3 4)
> (apply + '(1 2 3))
6
> (apply + (map car '((1 2) (3 4) (5 6))))
9

> (andmap positive? '(1 -2 a))
#f
> (andmap positive? '(1 2 a))
. . positive?: contract violation
  expected: real?
  given: 'a
> (andmap + '(1 2 3) '(4 5 6))
9
> (and 3 4)
4
> (and #f 4)
#f
> (and '() 4)
4
> (and 3 4 5)
5
> (andmap + '(1 2 3) '(4 5 6))
9
> (and 3 0)
0
> (ormap + '(1 2 3) '(4 5 6))
5
> (ormap + '(1 a s d) '(2 d f e))
3
> ((lambda (x y) (+ x y)) 3 4)
7
> (((lambda (x) (lambda (y) (+ x y))) 3) 4)
7
>