X-Git-Url: http://lambda.jimpryor.net/git/gitweb.cgi?p=lambda.git;a=blobdiff_plain;f=assignment1.mdwn;h=1c5dc9811536796dc52ebade7c949289ef5ebe89;hp=d14f792ff4615381b5fa2ad581538d1966b49647;hb=336e427a64c1956e15a722da848a906a149d42fd;hpb=c88cb71f06a27b98822b3580c5871c7429665674 diff --git a/assignment1.mdwn b/assignment1.mdwn index d14f792f..1c5dc981 100644 --- a/assignment1.mdwn +++ b/assignment1.mdwn @@ -1,8 +1,7 @@ Reduction --------- -Find "normal forms" for the following (that is, reduce them as far as it's possible to reduce -them): +Find "normal forms" for the following (that is, reduce them until no more reductions are possible): 1. (\x \y. y x) z 2. (\x (x x)) z @@ -81,7 +80,7 @@ To extract the first element of a pair p, you write: p (\fst \snd. fst) -Here are some defintions in Racket: +Here are some definitions in Racket: (define make-pair (lambda (fst) (lambda (snd) (lambda (f) ((f fst) snd))))) (define get-first (lambda (fst) (lambda (snd) fst))) @@ -137,7 +136,7 @@ your choice). (((make-triple M) N) P) -should return an object that behaves in a reasonable way to serve as a triple. In addition to defining the make-triple function, you have to show how to extraxt elements of your triple. Write a get-first-of-triple function, that does for triples what get-first does for pairs. Also write get-second-of-triple and get-third-of-triple functions. +should return an object that behaves in a reasonable way to serve as a triple. In addition to defining the make-triple function, you have to show how to extract elements of your triple. Write a get-first-of-triple function, that does for triples what get-first does for pairs. Also write get-second-of-triple and get-third-of-triple functions. * Write a function second-plus-third that when given to your triple, returns the result of adding the second and third members of the triple.