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(define exp
(lambda (a b)
(if (= b 1) a (* a (exp a (- b 1))))))
 
(define fib
(lambda (n)
(let ((fibn (floor (/ (exp (/ (+ 1 (sqrt 5)) 2) n) (sqrt 5)))))
(if (= 1 (modulo n 2)) (+ 1 fibn) fibn))))
 ...

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(define exp
(lambda (a b)
(if (= b 1) a (* a (exp a (- b 1))))))
 
(define fib
(lambda (n)
(let ((fibn (floor (/ (exp (/ (+ 1 (sqrt 5)) 2) n) (sqrt 5)))))
(if (!= 0 (modulo n 2)) (+ 1 fibn) fibn))))
 ...

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(define exp
(lambda (a b)
(if (= b 1) a (* a (exp a (- b 1))))))
 
(define fib
(lambda (n)
(let ((fibn (floor (/ (exp (/ (+ 1 (sqrt 5)) 2) n) (sqrt 5)))))
(if (= 0 (modulo n 2)) (+ 1 fibn) fibn))))
 ...

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(write (floor (/ 23 2)))

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(write (/ 23 2))

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(define exp
(lambda (a b)
(if (= b 1) a (* a (exp a (- b 1))))))
 
(define fib
(lambda (n)
(let ((fibn (/ (exp (/ (+ 1 (sqrt 5)) 2) n) (sqrt 5))))
(if (= 0 (modulo n 2)) (+ 1 fibn) fibn ))))

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(define exp
(lambda (a b)
(if (= b 1) a (* a (exp a (- b 1))))))
 
(define fib
(lambda (n)
(let ((fibn (/ (exp (/ (+ 1 (sqrt 5)) 2) n) (sqrt 5)))))
(if (= 0 (modulo n 2)) (+ 1 fibn) fibn )))

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(define exp
(lambda (a b)
(if (= b 1) a (* a (exp a (- b 1))))))
 
(define fib
(lambda (n)
(if (= 0 (modulo n 2)) (+ 1 (fibn (/ (exp (/ (+ 1 (sqrt 5)) 2) n) (sqrt 5)))) (fibn (/ (exp (/ (+ 1 (sqrt 5)) 2) n) (sqrt 5))))))
 
(write (fib 10))

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(define exp
(lambda (a b)
(if (= b 1) a (* a (exp a (- b 1))))))
 
(define fib
(lambda (n)
(if (= 0 (modulo n 2)) (+ 1 (fibn (/ (exp (/ (+ 1 (sqrt 5)) 2) n) (sqrt 5)))) (fibn (/ (exp (/ (+ 1 (sqrt 5)) 2) n) (sqrt 5))))))
 
    
 ...

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(define exp
(lambda (a b)
(if (= b 1) a (* a (exp a (- b 1))))))
 
(define fib
(lambda (n)
(if (= 0 (modulo n 2)) 1 2)))
 
(write (fib 10))

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(define exp
(lambda (a b)
(if (= b 1) a (* a (exp a (- b 1))))))
 
(define fib
(lambda (n)
(if (= 0 (modulo (n 2))) 1 2)))
 
(write (fib 10))

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(define exp
(lambda (a b)
(if (= b 1) a (* a (exp a (- b 1))))))
 
(define fib
(lambda (n)
(if (= 0 (modulo (n 2))) (+ 1 (fibn (/ (exp (/ (+ 1 (sqrt 5)) 2) n) (sqrt 5)))) (fibn (/ (exp (/ (+ 1 (sqrt 5)) 2) n) (sqrt 5))))))
 
(write (fib 10))

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(define exp
(lambda (a b)
(if (= b 1) a (* a (exp a (- b 1))))))
 
(define fib
(lambda (n)
(if (= 0 (modulo (n 2))) (+ 1 (fibn (/ (exp (/ (+ 1 (sqrt 5)) 2) i) (sqrt 5)))) (fibn (/ (exp (/ (+ 1 (sqrt 5)) 2) i) (sqrt 5))))))
 
(write (fib 10))

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(define exp
(lambda (a b)
(if (= b 1) a (* a (exp a (- b 1))))))
 
(define fib
(lambda (n)
(if (= 0 (modulo (n 2))) (+ 1 (fibn (/ (exp (/ (+ 1 (sqrt 5)) 2) i) (sqrt 5)))) (fibn (/ (exp (/ (+ 1 (sqrt 5)) 2) i) (sqrt 5))))))
 
    
 ...

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(write (+ 1 1))

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(define exp
(lambda (a b)
(if (= b 1) a (* a (exp a (- b 1))))))
 
(define fib
(lambda (n)
(let ((fibn (/ (exp (/ (+ 1 (sqrt 5)) 2) i) (sqrt 5)))))
(if (= 0 (modulo (n 2))) (+ 1 fibn) fibn)))
 ...

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(define (primes n) ; assumes n is an integer greater than one
  (let* ((len (quotient (- n 1) 2)) (bits (make-vector len #t)))
    (let loop ((i 0) (p 3) (ps (list 2))) ; sieve of eratosthenes
      (cond ((< n (* p p))
              (do ((i i (+ i 1)) (p p (+ p 2))
                   (ps ps (if (vector-ref bits i) (cons p ps) ps)))
                  ((= i len) (reverse ps))))
            ((vector-ref bits i)
                (do ((j (+ (* 2 i i) (* 6 i) 3) (+ j p)))
 ...

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(define-syntax new-object
    (syntax-rules (variables methods)
        ((_ prototype
            (variables (vname vval) ...)
            (methods (mname (margs ...) mbody ...) ...))
         (let ((super prototype) (vname vval) ...)
             (define (self msg . args) (case msg
                 ((vname) vname)
                 ...
 ...

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(define filter
  (lambda (pred? lst)
    (cond
      ((null? lst) '())
      ((pred? (car lst)) (cons (car lst) (filter pred? (cdr lst))))
      (else (filter pred? (cdr lst))))))
 
(define part
  (lambda (pred? yes no lst)
 ...

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(define filter
  (lambda (pred? lst)
    (cond
      ((null? lst) '())
      ((pred? (car lst)) (cons (car lst) (filter pred? (cdr lst))))
      (else (filter pred? (cdr lst))))))
 
(define part
  (lambda (pred? yes no lst)
 ...

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(define filter
  (lambda (pred? lst)
    (cond
      ((null? lst) '())
      ((pred? (car lst)) (cons (car lst) (filter pred? (cdr lst))))
      (else (filter pred? (cdr lst))))))
 
(define part
  (lambda (pred? yes no lst)
 ...

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(define filter
  (lambda (pred? lst)
    (cond
      ((null? lst) '())
      ((pred? (car lst)) (cons (car lst) (filter pred? (cdr lst))))
      (else (filter pred? (cdr lst))))))
 
(define part
  (lambda (pred? yes no lst)
 ...

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(define filter
  (lambda (pred? lst)
    (cond
      ((null? lst) '())
      ((pred? (car lst)) (cons (car lst) (filter pred? (cdr lst))))
      (else (filter pred? (cdr lst))))))
 
(define part
  (lambda (pred? yes no lst)
 ...

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(define filter
  (lambda (pred? lst)
    (cond
      ((null? lst) '())
      ((pred? (car lst)) (cons (car lst) (filter pred? (cdr lst))))
      (else (filter pred? (cdr lst))))))
 
(define part
  (lambda (pred? yes no lst)
 ...

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(define filter
  (lambda (pred? lst)
    (cond
      ((null? lst) '())
      ((pred? (car lst)) (cons (car lst) (filter pred? (cdr lst))))
      (else (filter pred? (cdr lst))))))
 
(define part
  (lambda (pred? yes no lst)
 ...

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(define filter
  (lambda (pred? lst)
    (cond
      ((null? lst) '())
      ((pred? (car lst)) (cons (car lst) (filter pred? (cdr lst))))
      (else (filter pred? (cdr lst))))))
 
(define partition
  (lambda (pred? lst)
 ...

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(define filter
  (lambda (pred? lst)
    (cond
      ((null? lst) '())
      ((pred? (car lst)) (cons (car lst) (filter pred? (cdr lst))))
      (else (filter pred? (cdr lst))))))
 
(define partition
  (lambda (pred? lst)
 ...

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(define filter
  (lambda (pred? lst)
    (cond
      ((null? lst) '())
      ((pred? (car lst)) (cons (car lst) (filter pred? (cdr lst))))
      (else (filter pred? (cdr lst))))))
 
(display (filter (lambda (x) (or (odd? x) (> x 3))) '(1 2 3 4 5)))

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(define filter
  (lambda (pred? lst)
    (cond
      ((null? lst) '())
      ((pred? (car lst)) (cons (car lst) (filter pred? (cdr lst))))
      (else (filter pred? (cdr lst))))))
 
(display (filter (lambda (x) (or (odd? x) (> x 3)) '(1 2 3 4 5)))

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(define filter
  (lambda (pred? lst)
    (cond
      ((null? lst) '())
      ((pred? (car lst)) (cons (car lst) (filter pred? (cdr lst))))
      (else (filter pred? (cdr lst))))))
 
(display (filter (lambda (x) (odd? x)) '(1 2 3 4 5)))