But where is the reasoning that led us to this unit and bind?
And what is the type `['a]`? Magic.
-So let's make a completely useless digression and see if we can
-gain some insight into the details of the List monad. Let's choose
-type constructor that we can peer into, using some of the technology
-we built up so laboriously during the first half of the course. I'm
-going to use type 3 lists, partly because I know they'll give the
-result I want, but also because they're my favorite. These were the
-lists that made lists look like Church numerals with extra bits
-embdded in them:
+So let's indulge ourselves in a completely useless digression and see
+if we can gain some insight into the details of the List monad. Let's
+choose type constructor that we can peer into, using some of the
+technology we built up so laboriously during the first half of the
+course. I'm going to use type 3 lists, partly because I know they'll
+give the result I want, but also because they're my favorite. These
+were the lists that made lists look like Church numerals with extra
+bits embdded in them:
empty list: fun f z -> z
list with one element: fun f z -> f 1 z