X-Git-Url: http://lambda.jimpryor.net/git/gitweb.cgi?p=lambda.git;a=blobdiff_plain;f=week1.mdwn;h=5ea3f421e69234c88e0fd974a486ad61e580fae0;hp=7ea30c3d490fbeb0faeb58ca5514014f4fa07b97;hb=826badc8d42e8fa03f46abf36273d1daadf991e7;hpb=0d2b33a56cdeba0ca5c4fe605fcd4e7e6d5cdc3d diff --git a/week1.mdwn b/week1.mdwn index 7ea30c3d..5ea3f421 100644 --- a/week1.mdwn +++ b/week1.mdwn @@ -10,14 +10,7 @@ Sometimes these notes will expand on things mentioned only briefly in class, or Basics of Lambda Calculus ========================= -See also: - -* [Chris Barker's Lambda Tutorial](http://homepages.nyu.edu/~cb125/Lambda) -* [Lambda Animator](http://thyer.name/lambda-animator/) -* [Penn lambda calculator](http://www.ling.upenn.edu/lambda/) Pedagogical software developed by Lucas Champollion, Josh Tauberer and Maribel Romero. Linguistically oriented. -* MORE - -The lambda calculus we'll be focusing on for the first part of the course has no types. (Some prefer to say it instead has a single type---but if you say that, you have to say that functions from this type to this type also belong to this type. Which is weird.) +The lambda calculus we'll be focusing on for the first part of the course has no types. (Some prefer to say it instead has a single type---but if you say that, you have to say that functions from this type to this type also belong to this type. Which is weird... In fact, though, such types are studied, under the name "recursive type." More about these later in the seminar.) Here is its syntax: @@ -37,7 +30,6 @@ We'll tend to write `(λa M)` as just `(\a M)`, so we don't hav Application: `(M N)` -Some authors reserve the term "term" for just variables and abstracts. We'll probably just say "term" and "expression" indiscriminately for expressions of any of these three forms. Examples of expressions: @@ -131,7 +123,7 @@ because here the second occurrence of `y` is no longer free. There is plenty of discussion of this, and the fine points of how substitution works, in Hankin and in various of the tutorials we've linked to about the lambda calculus. We expect you have a good intuitive understanding of what to do already, though, even if you're not able to articulate it rigorously. -* MORE +* [More discussion in week 2 notes](/week2/#index1h1) Shorthand @@ -328,7 +320,7 @@ To read further about the relation between declarative or functional programming * [[!wikipedia Purely functional]] * [[!wikipedia Referential transparency (computer science)]] * [[!wikipedia Imperative programming]] - +* [[!wikipedia Side effect (computer science) desc="Side effects"]] Map @@ -338,7 +330,7 @@ Map Scheme (functional part) OCaml (functional part) -C, Java, Pasval
+C, Java, Python
Scheme (imperative part)