The Lambda Calculus

Nice article (the Stanford Encyclopedia of Philosophy has many more, btw.), but I like the "Introduction to Lambda Calculus" by Henk Barendregt (one of <i>the</i> people working in Lambda calculus, see for instance the citation to his book "The Lambda Calculus: Its syntax and semantics." in the references), which has the added benefit of being free:<p><a href="http://www.cse.chalmers.se/research/group/logic/TypesSS05/Extra/geuvers.pdf" rel="nofollow">http://www.cse.chalmers.se/research/group/logic/TypesSS05/Ex...</a> (also covers typed lambda calculus AFAIR)

The Lambda Calculus is more widely applicable than most people know too.<p>One of the dominant modeling paradigms in formal semantics (e.g. understanding the meaning of human language) is built around a typed lambda calculus called Montague Semantics (see <a href="http://plato.stanford.edu/entries/montague-semantics/" rel="nofollow">http://plato.stanford.edu/entries/montague-semantics/</a> )

If Church numerals’ unary representation bothers you, there is an efficient embedding of naturals in λ-calculus as linked lists of Booleans. Well, more efficient than the alternative…<p><a href="http://useless-factor.blogspot.com/2007/04/thoughts-on-church-numerals.html" rel="nofollow">http://useless-factor.blogspot.com/2007/04/thoughts-on-churc...</a>

Very nice article. The HTML version is free, the .pdf version which will be available after the 21st will cost you $10 a year---all things considered, a useful service at a very reasonable cost.

Does anybody know whether this is a good introduction for someone who plans to go over the Lambda Papers in detail in about two weeks?

Wow,<p>I had never noticed how <i>intension</i>, used here in "intensional definition", was a different word than intention. I wonder what percentage of people who looked at this stuff outside a formal classroom <i>haven't</i> been confused by this?<p><a href="http://en.wikipedia.org/wiki/Intensional_definition" rel="nofollow">http://en.wikipedia.org/wiki/Intensional_definition</a>

If this stuff interests you have a look at Matt Might's blog, it's full of interesting goodies and extremely accessible. For example:<p><a href="http://matt.might.net/articles/compiling-up-to-lambda-calculus/" rel="nofollow">http://matt.might.net/articles/compiling-up-to-lambda-calcul...</a>

You can see where the name 'Y Combinator' came from. Thanks.

The Stanford Encyclopedia of Philosophy, one of my favorite hangouts on the net for the last decade. Enjoy it.

what perent of programmers actually even use the lambda calculus?

nice