-Now, this implementation is a bit silly, since in order to convert the
-trees to leaf streams, our tree_monadizer function has to visit every
-node in the tree. But if we needed to compare each tree to a large
-set of other trees, we could arrange to monadize each tree only once,
-and then run compare_streams on the monadized trees.
+Now, you might think that this implementation is a bit silly, since in
+order to convert the trees to leaf streams, our tree_monadizer
+function has to visit every node in the tree, so we'd have to traverse
+the entire tree at some point. But you'd be wrong: part of what gets
+suspended in the thunking of the stream is the computation of the rest
+of the monadized tree. Proving this claim requires adding print
+statements (or other tracing technology) within the tree monadizer
+function.