X-Git-Url: http://lambda.jimpryor.net/git/gitweb.cgi?p=lambda.git;a=blobdiff_plain;f=assignment_3_evaluator.mdwn;h=c4032ee37c7f1ec456a09f7ed5a88093f932bd64;hp=f4f5fb929b3fa5b70d3fe27a0b9d77dde81a7170;hb=d50ce29231fc7454463b0a1b7b898022db6b67d1;hpb=d7c9144dc2558e867db336c1c36961fb0d19fdad

diff --git a/assignment_3_evaluator.mdwn b/assignment_3_evaluator.mdwn
index f4f5fb92..c4032ee3 100644
--- a/assignment_3_evaluator.mdwn
+++ b/assignment_3_evaluator.mdwn
@@ -48,7 +48,7 @@ let t3 = (make\_list 3 empty) in
 let t12 = (make\_list t1 (make\_list t2 empty)) in
 let t23 = (make\_list t2 (make\_list t3 empty)) in
 let ta = (make\_list t1 t23) in
-let tb = (make\_list t12 t3) in
+let tb = (make\_list t12 (make\_list t3 empty)) in
 let tc = (make\_list t1 (make\_list t23 empty)) in
 ;
 ;sum-leaves t1 ; ~~> 1
@@ -58,8 +58,13 @@ let tc = (make\_list t1 (make\_list t23 empty)) in
 ;sum-leaves t23 ; ~~> 5
 ;sum-leaves ta ; ~~> 6
 ;sum-leaves tb ; ~~> 6
+;sum-leaves tc ; ~~> 6 
 ;
-length (tail mylist)
+let add = \l r. l succ r in
+let fold = Y (\f g l z. isempty l z (g (head l)(f g (tail l) z))) in
+;
+; hint: 
+fold add mylist 0
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