*We will continue to develop these notes over the next few days.*
> Topics:
-Arithmetic with Church numbers (in progress);
+[[Arithmetic with Church numbers|topics/week3_church_arithmetic]];
+[[More on Lists|topics/week3 lists]] (expanded on Sunday);
[[What is computation?|topics/week3_what_is_computation]];
-[[More on Lists|topics/week3 lists]] (will be expanded);
-[[Combinatory Logic|topics/week3 combinatory logic]];
-Reduction Strategies and Normal Forms (in progress);
-Usefulness of `()` (in progress);
+[[Reduction Strategies and Normal Forms|topics/week3_evaluation_order]] (posted on Monday 23 Feb);
+[[Unit and its usefulness|topics/week3 unit]] (posted on Wednesday);
+[[Combinatory Logic|topics/week3 combinatory logic]] (revised on Monday and Tuesday);
[[Homework|exercises/assignment3]]
+> Also, by this point you should be able to handle all of *The Little Schemer* except for Chapters 9 and 10. Chapter 9 covers what is going on under the hood with `letrec`, and that will be our topic for next week. You can also read Chapter 4 of Hankin on Combinatory Logic.
-> Also, by this point you should be able to handle all of *The Little Schemer* except for Chapters 9 and 10. Chapter 9 covers what is going on under the hood with `letrec`, and that will be our topic for next week.
+> 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);
+[[Homework|exercises/assignment4]]
+
+> 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.
+
+> If you're reading along in the Pierce book, we've now covered much of the material in his Chapters 1-7.
+
+> We posted [[answers to Week 3's homework|exercises/assignment3_answers]].
+
+(**Week 5**) Thursday 26 February 2015
+
+> Topics:
+Simply-typed lambda calculus;
+System F;
+Types in OCaml and Haskell;
+Practical advice for working with OCaml and/or Haskell;
+Homework (all will be posted soon)
+
+> If you're reading along in Hankin, you can look at Chapter 7.
+
+> If you're reading along in the Pierce book, the chapters most relevant to this week's discussion are 22 and 23; though for context we also recommend at least Chapters 8, 9, 11, 20, and 29. We don't expect most of you to follow these recommendations now, or even to be comfortable enough yet with the material to be able to. We're providing the pointers as references that some might conceivably pursue now, and others later.
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