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-advanced-reader.ss" "lang")((modname |30.2|) (read-case-sensitive #t) (teachpacks ((lib "draw.ss" "teachpack" "htdp") (lib "arrow.ss" "teachpack" "htdp") (lib "gui.ss" "teachpack" "htdp"))) (htdp-settings #(#t constructor repeating-decimal #t #t none #f ((lib "draw.ss" "teachpack" "htdp") (lib "arrow.ss" "teachpack" "htdp") (lib "gui.ss" "teachpack" "htdp")))))
 4 12687dd9 2023-08-04 jrmu A node is a symbol.
 5 12687dd9 2023-08-04 jrmu 
 6 12687dd9 2023-08-04 jrmu A pair is a list
 7 12687dd9 2023-08-04 jrmu (cons n1 (cons n2)), ie, (list n1 n2)
 8 12687dd9 2023-08-04 jrmu where n1 and n2 are symbols representing nodes.
 9 12687dd9 2023-08-04 jrmu 
10 12687dd9 2023-08-04 jrmu A simple-graph is a (listof pairs).
11 12687dd9 2023-08-04 jrmu 
12 12687dd9 2023-08-04 jrmu route-exists? : node node sg (listof nodes) -> boolean