-be your base case for your recursive functions that operate on trees.
-
-Write a function that sums the number of leaves in a tree.
-Expected behavior:
-
-<pre>
-
-let t1 = (make-list 1 nil) in
-let t2 = (make-list 2 nil) in
-let t3 = (make-list 3 nil) in
-let t12 = (make-list t1 (make-list t2 nil)) in
-let t23 = (make-list t2 (make-list t3 nil)) in
-let ta = (make-list t1 t23) in
-let tb = (make-list t12 t3) in
-let tc = (make-list t1 (make-list t23 nil)) in
-
-count-leaves t1 ~~> 1
-count-leaves t2 ~~> 2
-count-leaves t3 ~~> 3
-count-leaves t12 ~~> 3
-count-leaves t23 ~~> 5
-count-leaves ta ~~> 6
-count-leaves tb ~~> 6
-count-leaves tc ~~> 6
-<pre>
-
-Write a function that counts the number of leaves.
-
-