From: Jim Pryor Date: Thu, 16 Sep 2010 03:28:32 +0000 (-0400) Subject: week1: markup problems fixed X-Git-Url: http://lambda.jimpryor.net/git/gitweb.cgi?p=lambda.git;a=commitdiff_plain;h=367daadad3a5d40885072b6b6f66ffd397e29c91 week1: markup problems fixed Signed-off-by: Jim Pryor --- diff --git a/week1.mdwn b/week1.mdwn index 1bc2309e..52654e3e 100644 --- a/week1.mdwn +++ b/week1.mdwn @@ -74,7 +74,7 @@ The lambda calculus has an associated proof theory. For now, we can regard the proof theory as having just one rule, called the rule of **beta-reduction** or "beta-contraction". Suppose you have some expression of the form: - ((\ a M) N) + ((\a M) N) that is, an application of an abstract to some other expression. This compound form is called a **redex**, meaning it's a "beta-reducible expression." `(\a M)` is called the **head** of the redex; `N` is called the **argument**, and `M` is called the **body**. @@ -286,7 +286,6 @@ It's possible to enhance the lambda calculus so that functions do get identified It's often said that dynamic systems are distinguished because they are the ones in which **order matters**. However, there are many ways in which order can matter. If we have a trivalent boolean system, for example---easily had in a purely functional calculus---we might choose to give a truth-table like this for "and": true and true = true - true and true = true true and * = * true and false = false * and true = * @@ -539,7 +538,7 @@ Here's how it looks to say the same thing in various of these languages. (let* [(bar (lambda (x) B))] M) - then wherever `bar` occurs in `M` (and isn't rebound by a more local "let" or "lambda"), it will be interpreted as the function `(lambda (x) B)`. + then wherever `bar` occurs in `M` (and isn't rebound by a more local `let` or `lambda`), it will be interpreted as the function `(lambda (x) B)`. Similarly, in OCaml: @@ -599,7 +598,7 @@ Here's how it looks to say the same thing in various of these languages. let x = A;; ... rest of the file or interactive session ... - It's easy to be lulled into thinking this is a kind of imperative construction. *But it's not!* It's really just a shorthand for the compound "let"-expressions we've already been looking at, taking the maximum syntactically permissible scope. (Compare the "dot" convention in the lambda calculus, discussed above.) + It's easy to be lulled into thinking this is a kind of imperative construction. *But it's not!* It's really just a shorthand for the compound `let`-expressions we've already been looking at, taking the maximum syntactically permissible scope. (Compare the "dot" convention in the lambda calculus, discussed above.) 9. Some shorthand @@ -749,7 +748,7 @@ Or even: (define foo B) (foo 2) -don't involve any changes or sequencing in the sense we're trying to identify. As we said, these programs are just syntactic variants of (single) compound syntactic structures involving "let"s and "lambda"s. +don't involve any changes or sequencing in the sense we're trying to identify. As we said, these programs are just syntactic variants of (single) compound syntactic structures involving `let`s and `lambda`s. Since Scheme and OCaml also do permit imperatival constructions, they do have syntax for genuine sequencing. In Scheme it looks like this: