X-Git-Url: http://lambda.jimpryor.net/git/gitweb.cgi?p=lambda.git;a=blobdiff_plain;f=index.mdwn;h=8f0e0c6ea756a95be6b19a1b6cdc3f13c6c1029d;hp=039035011f99d9f0ebe7592903e3c6b9c818ea5d;hb=54566d57756ec32f26dd22ec4a8258be7d3c5ebb;hpb=0da178367cda4feaf08df9a101b7d36eedee9f58

diff --git a/index.mdwn b/index.mdwn
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+++ 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]].