+Trivia: what's the type of the `raise (Failure "two")` in:
+
+ if x = 1 then 10
+ else raise (Failure "two")
+
+What's its type in:
+
+ if x = 1 then "ten"
+ else raise (Failure "two")
+
+So now what do you expect the type of this to be:
+
+ fun x -> raise (Failure "two")
+
+How about this:
+
+ (fun x -> raise (Failure "two") : 'a -> 'a)
+
+Remind you of anything we discussed earlier? /Trivia.
+