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 "+" 4 5) (+ 4 5)) (EXAMPLE (mystery "sqrt" 25)) (sqrt 25))
no match (the domains have different numbers of arguments)
(EXAMPLE (mystery (triangle 70 "solid" "green")) (triangle 140 "solid" "green")) (EXAMPLE (mystery (circle 100 "solid" "blue")) (circle 200 "solid" "blue"))
; mystery : image -> image
(EXAMPLE (mystery "red") (triangle 140 "solid" "red")) (EXAMPLE (mystery "blue" "circle")) (circle 140 "solid" "blue"))
no match (the domains have different numbers of arguments)
(EXAMPLE (mystery "circle" 4) (* pi (sqr 4))) (EXAMPLE (mystery "square" 5)) (sqr 5))
; mystery : string number -> number
(EXAMPLE (mystery "dog") 3) (EXAMPLE (mystery "cat") "kitten")
no match (the range types are different)
(EXAMPLE (mystery "dog") 3) (EXAMPLE (mystery "kitten") 6)
; mystery : string -> number
(EXAMPLE (mystery 4 5 "big") (scale 2 (rectangle 4 5 "solid" "blue"))) (EXAMPLE (mystery 10 "small" 4) (scale .5 (rectangle 10 4 "solid" "blue")))
no match (the domains have different orders of arguments)

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.