Assignment 3
------------
+Erratum corrected 11PM Sun 3 Oct: the following line
+
+ let tb = (make_list t12 (make_list t3 empty)) in
+
+originally read
+
+ let tb = (make_list t12 t3) in
+
+This has been corrected below, and in the preloaded evaluator for
+working on assignment 3.
+
+
+
Once again, the lambda evaluator will make working through this
assignment much faster and more secure.
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