Initializing the A++ Interpreter part 3

(define compose (lambda (f g)
                  (lambda (x) 
                    (f (g x)))))
(define add    (lambda (m n)
                 (lambda (f) 
                   (compose (m f) (n f)))))
(define succ   (lambda (n) 
                 (lambda (f) 
                   (compose  f (n f)))))
(define mult   (lambda (m n)
                 (compose m n)))
(define length (lambda (l) 
                 (if (nullp l) 
                     zero
                     (add one (length (cdr l))))))
(define zeropair (cons zero zero))
(define pred   (lambda (n) 
                 (cdr ((n (lambda (x) 
                            (cons (add (car x) one)
                                  (car x))))
                       zeropair))))
(define sub    (lambda (m n)
                 ((n pred) m)))
;

Georg P. Loczewski 2004-03-05

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