Merge branch 'pryor'

diff --git a/assignment2.mdwn b/assignment2.mdwn
index 648ef21..ff600cc 100644 (file)
--- a/assignment2.mdwn
+++ b/assignment2.mdwn
@@ -33,6 +33,36 @@ Reduce to beta-normal forms:
 <LI>`(\x y z. x z (y z)) (\u v. u)`
 </OL>
 
+Combinatory Logic
+-----------------
+
+Reduce the following forms, if possible:
+
+<OL start=16>
+<LI> `Kxy`
+<LI> `KKxy`
+<LI> `KKKxy`
+<LI> `SKKxy`
+<LI> `SIII`
+<LI> `SII(SII)`
+
+<LI> Give Combinatory Logic combinators that behave like our boolean functions.
+  You'll need combinators for `true`, `false`, `neg`, `and`, `or`, and `xor`.
+</OL>
+
+Using the mapping specified in the lecture notes,
+translate the following lambda terms into combinatory logic:
+
+<OL start=23>
+<LI> `\x.x`
+<LI> `\xy.x`
+<LI> `\xy.y`
+<LI> `\xy.yx`
+<LI> `\x.xx`
+<LI> `\xyz.x(yz)`
+<LI> For each translation, how many I's are there?  Give a rule for 
+   describing what each I corresponds to in the original lambda term.
+</OL>
 
 Lists and Numbers
 -----------------

diff --git a/index.mdwn b/index.mdwn
index aeb0564..46f6b74 100644 (file)
--- a/index.mdwn
+++ b/index.mdwn
@@ -16,11 +16,14 @@ Student sessions will be held on Tuesdays from 11-12 and Wednesdays from 3-4. (Y
 
 Lots of lecture notes summarizing and expanding on last Monday's seminar now posted. Also, lecture notes for upcoming session have been posted. (Click "Notes and Schedule".)
 
-## Assignments ##
+## Lecture Notes and Assignments ##
 
-[[Assignment1]]
+Lecture notes for [[Week1]]; [[Assignment1]].
 
-[[Assignment2]]
+Lecture notes for [[Week2]]; [[Assignment2]].
+
+There is now a [lambda evaluator](lambda-let.html) you can use in your browser (no need to install any software).
+It can help you check whether your answer to some of the homework questions works correctly.
 
 [Lambda Calculator](/lambda-let.html)