X-Git-Url: http://lambda.jimpryor.net/git/gitweb.cgi?p=lambda.git;a=blobdiff_plain;f=hints%2Fassignment_7_hint_2.mdwn;h=9c1079c3858e0ad4ba53b24fcf85ae08d58efb24;hp=96e47410540b85308d99988ab90d3dd81a8df9b4;hb=3ed8e56bf33b1c0cfa09b672abf26e9c397ea0f1;hpb=6da4e7b4835a68593ed7996f7cb4e577aed625c7

diff --git a/hints/assignment_7_hint_2.mdwn b/hints/assignment_7_hint_2.mdwn
index 96e47410..9c1079c3 100644
--- a/hints/assignment_7_hint_2.mdwn
+++ b/hints/assignment_7_hint_2.mdwn
@@ -20,9 +20,9 @@
 
 	Since `dpm`s are to be a monad, we have to define a unit and a bind. These are just modeled on the unit and bind for the state monad:
 
-		let unit_dpm (x : 'a) = fun (r, h) -> (x, r, h);;
+		let unit_dpm (value : 'a) : 'a dpm = fun (r, h) -> (value, r, h);;
 
-		let bind_dpm (u : 'a dpm) (f : 'a -> 'b dpm) =
+		let bind_dpm (u : 'a dpm) (f : 'a -> 'b dpm) : 'b dpm =
 			fun (r, h) ->
 				let (a, r', h') = u (r, h)
 				in let u' = f a
@@ -30,5 +30,5 @@
 
 *	A *possibility* for GS&V is a triple of an assignment function `r`, a store `h`, and a world `w`. We're dropping worlds so we'll call pairs `(r, h)` *discourse possibilities*. *dpm*s are monads that represent computations that may mutate---or in GS&V's terminology "extend"---discourse possibilities. An `'a dpm` is a function that takes a starting `(r, h)` and returns an `'a` and a possibly mutated `r'` and `h'`.
 
-*	Is that enough? If not, here are some [more hints](/hints/assignment_7_hint_3).
+*	Is that enough? If not, here are some [more hints](/hints/assignment_7_hint_3). But try to get as far as you can on your own.