Implementation of Points

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(define (first-dimension point) (car point))
(define (other-dimensions point) (cdr point))
(define (zero-dimension? point) (null? point))

(define origin-3d (list 0 0 0))
(define p1 (list 2 3))
(define p2 (list 3 4))
(define p3 (list 2 7))

(distance p1 p2)
(distance p1 p3)
(distance p3 p1)
Jim Miller W3C