Scheme stuff

scheme_stuff.scm

(define sigma
  (lambda (a form next b)
    (if (> a b)
        0
        (+ (form a) (sigma (next a) form next b)))))

(define sumsq
  (lambda (m n)
    (sigma m (lambda (k) (* k k)) (lambda (k) (+ k 1)) n)))

(define sumrep
  (lambda (m n)
    (sigma m (lambda (k) (/ 1 k)) (lambda (k) (+ k 2)) n)))

(define expo
  (lambda (a b)
    (if (= b 0)
        1
        (* a (expo a (- b 1))))))