(define (make-frame origin edge1 edge2)
(list origin edge1 edge2))
(define (edge1-frame frame) (cadr frame))
(define (edge2-frame frame) (caddr frame))
(define (origin-frame frame) (car frame))
(define f1 (make-frame (cons 1 2) 1 2))
(edge1-frame f1)
(edge2-frame f1)
(origin-frame f1)
(define (make-frame origin edge1 edge2)
(cons origin (cons edge1 edge2)))
(define (edge1-frame frame) (cadr frame))
(define (edge2-frame frame) (cddr frame))
(define (origin-frame frame) (car frame))
(define f1 (make-frame (cons 1 2) 1 2))
(edge1-frame f1)
(edge2-frame f1)
(origin-frame f1)