> Topics:
[[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);
+[[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.
<!--