edits

[lambda.git] / assignment_3_evaluator.mdwn

diff --git a/assignment_3_evaluator.mdwn b/assignment_3_evaluator.mdwn
index f4f5fb9..c4032ee 100644 (file)
--- 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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