X-Git-Url: http://lambda.jimpryor.net/git/gitweb.cgi?p=lambda.git;a=blobdiff_plain;f=week1.mdwn;h=4981c1a325d668e297ed33f74de1dfdd19937727;hp=967f8144e1b586272051a4667b8bc0b9f2b22df4;hb=e4e6297f595a47a91da3af55a2433b5e9913132e;hpb=8e91eed999622b45d169949f7f7de32f491e20e7 diff --git a/week1.mdwn b/week1.mdwn index 967f8144..4981c1a3 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: @@ -130,7 +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 @@ -356,17 +349,13 @@ combinatorial logic -[Correction: OCaml is Turing complete, but I'm not sure if the merely functional part is; I suspect it's not.] - Rosetta Stone ============= Here's how it looks to say the same thing in various of these languages. -The following site may be useful; it lets you run a Scheme interpreter inside your web browser: - -* [Try Scheme in your web browser](http://tryscheme.sourceforge.net/) +The following site may be useful; it lets you run a Scheme interpreter inside your web browser: [Try Scheme in your web browser](http://tryscheme.sourceforge.net/). See also our links about [[learning Scheme]] and [[learning OCaml]].