1 12687dd9 2023-08-04 jrmu ;; The first three lines of this file were inserted by DrScheme. They record metadata
 2 12687dd9 2023-08-04 jrmu ;; about the language level of this file in a form that our tools can easily process.
 3 12687dd9 2023-08-04 jrmu #reader(lib "htdp-intermediate-reader.ss" "lang")((modname 18.1.14) (read-case-sensitive #t) (teachpacks ((lib "draw.ss" "teachpack" "htdp"))) (htdp-settings #(#t constructor repeating-decimal #f #t none #f ((lib "draw.ss" "teachpack" "htdp")))))
 4 12687dd9 2023-08-04 jrmu ;A web-page (wp) is a structure:
 5 12687dd9 2023-08-04 jrmu ;(make-wp header doc) where
 6 12687dd9 2023-08-04 jrmu ;header is a symbol and doc is
 7 12687dd9 2023-08-04 jrmu ;a web-document.
 8 12687dd9 2023-08-04 jrmu ;
 9 12687dd9 2023-08-04 jrmu ;A web-document (doc) is either
10 12687dd9 2023-08-04 jrmu ;1. empty,
11 12687dd9 2023-08-04 jrmu ;2. (cons sym doc) where sym is a symbol and
12 12687dd9 2023-08-04 jrmu ;doc is a web-document, or
13 12687dd9 2023-08-04 jrmu ;3. (cons wp doc) where wp is a webpage and
14 12687dd9 2023-08-04 jrmu ;doc is a web-document.
15 12687dd9 2023-08-04 jrmu 
16 12687dd9 2023-08-04 jrmu (define-struct wp (header doc))
17 12687dd9 2023-08-04 jrmu 
18 12687dd9 2023-08-04 jrmu ;find : wp symbol -> list-of-symbols/false
19 12687dd9 2023-08-04 jrmu ;Given a-wp and a-symbol, return the headers
20 12687dd9 2023-08-04 jrmu ;of the web-pages that are accessed on the way
21 12687dd9 2023-08-04 jrmu ;to locating a-symbol.  Returns false
22 12687dd9 2023-08-04 jrmu ;if a-symbol never occurs.
23 12687dd9 2023-08-04 jrmu 
24 12687dd9 2023-08-04 jrmu (define (find a-wp a-symbol)
25 12687dd9 2023-08-04 jrmu   (cond
26 12687dd9 2023-08-04 jrmu     []
27 12687dd9 2023-08-04 jrmu     []
28 12687dd9 2023-08-04 jrmu     []))