X-Git-Url: http://lambda.jimpryor.net/git/gitweb.cgi?p=lambda.git;a=blobdiff_plain;f=assignment4.mdwn;h=9b7ec2c028622dc92e17dced54403aa6043b8896;hp=6a528a23c943a8f0b3a0e909f999092f657f900d;hb=c3395c03cdde647d084ca1ca2917adf7c3ec3838;hpb=9888d5cbf679f92c7447c7d4eb06ad407e974f94 diff --git a/assignment4.mdwn b/assignment4.mdwn index 6a528a23..9b7ec2c0 100644 --- a/assignment4.mdwn +++ b/assignment4.mdwn @@ -64,14 +64,15 @@ 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. +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, 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. +implementation of trees you designed in the previous step. +Then combine this with the list comparison function you wrote for question 2, +to yield a same-fringe detector. (To use your list comparison function, you'll +have to make sure you only use Church numerals as the labels of your leaves, +though nothing enforces this self-discipline.)