add anchor for #lightweight

[lambda.git] / topics / _week2_lambda_calculus_intro.mdwn

diff --git a/topics/_week2_lambda_calculus_intro.mdwn b/topics/_week2_lambda_calculus_intro.mdwn
index 68beb1c..d393be1 100644 (file)
--- a/topics/_week2_lambda_calculus_intro.mdwn
+++ b/topics/_week2_lambda_calculus_intro.mdwn
@@ -43,8 +43,9 @@ grammar:
 
     T --> ( T T )
     T --> ( lambda Var T)
-    T --> x
-    T --> y
+    Var --> x
+    Var --> y
+    Var --> z
     ...
 
 Very, very simple.
@@ -218,7 +219,7 @@ a unique result.
 
 The essential usefullness of the lambda calculus is that it is
 wonderfully suited to representing functions.  In fact, the untyped
-lambda calculus is Turing Complete [[!wikipedia Turing Completeness]]:
+lambda calculus is Turing Complete (see [[!wikipedia Turing Completeness]]):
 all (recursively computable) functions can be represented by lambda
 terms.  (As we'll see, much of the fun will be in unpacking the word
 "represented".)
@@ -340,10 +341,10 @@ need to do some work to show how to represent some of the functions
 we've become acquainted with.  We'll start with the `if ... then
 ... else...` construction.
 
-    if x then y else z
+    if M then N else L
 
-For a boolean expression `x`, this complex expression evaluates to `y`
-if `x` evaluates to `'true`, and to `z` if `x` evaluations to `'false.
+For a boolean expression `M`, this complex expression evaluates to `N`
+if `M` evaluates to `'true`, and to `L` if `M` evaluations to `'false.
 So in order to simulate and `if` clause in the lambda calculus, we
 need to settle on a way to represent `'true` and `'false`.