revised inf arithmetic question again, like to ordinals, cardinals

[lambda.git] / index.mdwn

diff --git a/index.mdwn b/index.mdwn
index 0390350..8f0e0c6 100644 (file)
--- a/index.mdwn
+++ b/index.mdwn
@@ -110,7 +110,7 @@ The [[differences between our made-up language and Scheme, OCaml, and Haskell|ro
 [[More on Lists|topics/week3 lists]] (expanded on Sunday);
 [[What is computation?|topics/week3_what_is_computation]];
 Reduction Strategies and Normal Forms (in progress);
-Usefulness of `()` (in progress);
+[[Unit and its usefulness|topics/week3 unit]] (posted on Wednesday);
 [[Combinatory Logic|topics/week3 combinatory logic]] (revised on Monday and Tuesday);
 [[Homework|exercises/assignment3]]
 
@@ -118,6 +118,16 @@ Usefulness of `()` (in progress);
 
 > We posted [[answers to Week 2's homework|exercises/assignment2_answers]].
 
+(**Week 4**) Thursday 19 February 2015
+
+> Topics: [[!img images/tabletop_roleplaying.png size="240x240" alt="Hey, no recursing"]]
+[[Yes, recursing|topics/week4_fixed_point_combinators]];
+[[More about fixed point combinators|topics/week4_more_about_fixed_point_combinators]];
+Towards types (in progress)
+
+> Now you can read Sections 3.1 and 6.1 of Hankin; and browse the rest of Hankin Chapter 6, which should look somewhat familiar.
+
+
 <!--
 We've added a [[Monad Library]] for OCaml.
 We've posted a [[State Monad Tutorial]].