X-Git-Url: http://lambda.jimpryor.net/git/gitweb.cgi?p=lambda.git;a=blobdiff_plain;f=assignment4.mdwn;h=6a528a23c943a8f0b3a0e909f999092f657f900d;hp=7073dc6b188c3c022289937e451e00840ddf0f30;hb=9888d5cbf679f92c7447c7d4eb06ad407e974f94;hpb=93875f124b3af0b7e114373588fa110d79f9abc0 diff --git a/assignment4.mdwn b/assignment4.mdwn index 7073dc6b..6a528a23 100644 --- a/assignment4.mdwn +++ b/assignment4.mdwn @@ -64,12 +64,14 @@ return later in the term to the problem of determining when two trees have the same fringe. For now, one straightforward way to determine this would be: enumerate the fringe of the first tree. That gives you a list. Enumerate the fringe of the second tree. That also gives you a list. Then compare the two -lists to see if they're equal. (You just programmed this above.) +lists to see if they're equal. -Write the fringe-enumeration function. It should work on the implementation of -trees you designed in the previous step. +Write the fringe-enumeration function. It should work on the +implementation of trees you designed in the previous step, and it +should make use of the list comparison function you wrote for question +2. Thus you'll have to make sure you only use Church numerals as the +labels of your leaves, though nothing enforces this self-discipline. -(See [[hints/Assignment 4 hint 3]] if you need some hints.) @@ -134,7 +136,7 @@ definitions of `even` and `odd`? notes](/week3/#index4h2) as a model, construct a pair `Y1` and `Y2` that behave in the way described. -(See [[hints/Assignment 4 hint 4]] if you need some hints.) +(See [[hints/Assignment 4 hint 3]] if you need some hints.)