Skip to content

Instantly share code, notes, and snippets.

@Sophia-Gold

Sophia-Gold/church.scm

Created April 22, 2018 02:03
Show Gist options

  • Select an option

    Learn more about clone URLs
  • Save Sophia-Gold/52e678645c8f9d60dd5180b13cc4de62 to your computer and use it in GitHub Desktop.

Select an option

Learn more about clone URLs
Save Sophia-Gold/52e678645c8f9d60dd5180b13cc4de62 to your computer and use it in GitHub Desktop.
Download ZIP
church numerals
Raw
church.scm
(define zero (lambda (f) (lambda (x) x)))
(define one (lambda (f) (lambda (x) (f x))))
(define two (lambda (f) (lambda (x) (f (f x)))))
(define three (lambda (f) (lambda (x) (f (f (f x))))))
(define four (lambda (f) (lambda (x) (f (f (f (f x)))))))
(define five (lambda (f) (lambda (x) (f (f (f (f (f x))))))))
(define six (lambda (f) (lambda (x) (f (f (f (f (f (f x)))))))))
(define seven (lambda (f) (lambda (x) (f (f (f (f (f (f (f x))))))))))
(define eight (lambda (f) (lambda (x) (f (f (f (f (f (f (f (f x)))))))))))
(define nine (lambda (f) (lambda (x) (f (f (f (f (f (f (f (f (f x))))))))))))
(define (succ n) (lambda (f) (lambda (x) (f ((n f) x)))))
(define (add m n) (lambda (f) (lambda (x) ((m f) ((n f) x)))))
(define (mult m n) (lambda (f) (lambda (x) ((m (n f)) x))))
(define (pow m n) (lambda (f) (lambda (x) (((n m) f) x))))
(define (pred n) (lambda (f) (lambda (x) (((n (lambda (g) (lambda (h) (h (g f))))) (lambda (u) x)) (lambda (u) u)))))
(define (sub m n) (lambda (f) (lambda (x) ((((n pred) m) f) x))))
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment