From: Jim Pryor Date: Thu, 16 Sep 2010 01:20:18 +0000 (-0400) Subject: week1: tweaks X-Git-Url: http://lambda.jimpryor.net/git/gitweb.cgi?p=lambda.git;a=commitdiff_plain;h=6f6f2258d5229e875dc926d1777a37664ea4cbef week1: tweaks Signed-off-by: Jim Pryor --- diff --git a/week1.mdwn b/week1.mdwn index e6a6bd93..14e68c98 100644 --- a/week1.mdwn +++ b/week1.mdwn @@ -66,7 +66,7 @@ It's often said that dynamic systems are distinguished because they are the ones false and * = false false and false = false -And then we'd notice that `* and false` has a different intepretation than `false and *`. (The same phenomenon is already present with the mateial conditional in bivalent logics; but seeing that a non-symmetric semantics for `and` is available even for functional languages is instructive.) +And then we'd notice that ` * and false` has a different intepretation than `false and *`. (The same phenomenon is already present with the mateial conditional in bivalent logics; but seeing that a non-symmetric semantics for `and` is available even for functional languages is instructive.) Another way in which order can matter that's present even in functional languages is that the interpretation of some complex expressions can depend on the order in which sub-expressions are evaluated. Evaluated in one order, the computations might never terminate (and so semantically we interpret them as having "the bottom value"---we'll discuss this). Evaluated in another order, they might have a perfectly mundane value. Here's an example, though we'll reserve discussion of it until later: @@ -258,7 +258,7 @@ Here's how it looks to say the same thing in various of these languages. (let ((two 2)) (+ three two))) - Scheme also has a simple `let` (without the `*`), and it permits you to group several variable bindings together in a single `let`- or `let*`-statement, like this: + Scheme also has a simple `let` (without the ` *`), and it permits you to group several variable bindings together in a single `let`- or `let*`-statement, like this: (let* ((three 3) (two 2)) (+ three two))