Exercise: Do Examples Have the Same Contracts?

Directions: For each pairs of Examples below, decide whether the two examples have the same contract. If they do, fill in the contract in the space provided. If not, write a few words explaining why.

(EXAMPLE (mystery 30) (* 30 50)) (EXAMPLE (mystery 10) (text "Welcome!" 10 "darkgreen"))
no match (the range types are different)
(EXAMPLE (mystery 30 40) (- 40 (* 2 30))) (EXAMPLE (mystery 10 15) (- 15 (* 2 10)))
; mystery : number number -> number
(EXAMPLE (mystery "New York") (text "New York" 20 "red")) (EXAMPLE (mystery 20) (text "New York" 20 "red"))
no match (the domain types are different)
(EXAMPLE (mystery "green" 32) (circle 32 "outline" "green")) (EXAMPLE (mystery 18 "green") (circle 18 "outline" "green"))
no match (the domain types are in different orders)
(EXAMPLE (mystery 6 9 10) (/ 6 (+ 9 10))) (EXAMPLE (mystery 3 7) (/ 3 (+ 7 10)))
no match (the domains have different numbers of arguments)
(EXAMPLE (mystery "red" "blue") (text "blue" 25 "red")) (EXAMPLE (mystery "purple" "Go Team!") (text "Go Team!" 25 "purple"))
; mystery : string string -> image
(EXAMPLE (mystery (circle 55 "outline" "black") 12) (scale 12 (circle 55 "outline" "black"))) (EXAMPLE (mystery (rectangle 24 32 "outline" "purple") 5) (scale 5 (rectangle 24 32 "outline" "purple")))
; mystery : image number -> image

Bootstrap:Algebra by Emmanuel Schanzer, Emma Youndtsmith, Kathi Fisler, and Shriram Krishnamurthi is licensed under a Creative Commons 4.0 Unported License. Based on a work at www.BootstrapWorld.org. Permissions beyond the scope of this license may be available by contacting schanzer@BootstrapWorld.org.