X-Git-Url: http://lambda.jimpryor.net/git/gitweb.cgi?p=lambda.git;a=blobdiff_plain;f=week1.mdwn;h=cacb73fc61c4d49d4b4afa2cf2c4df05d533447e;hp=a5e697a5026751b9fb6b261f657cd2f91f69c99a;hb=4400e0ff673a6a5d642da62977098a5ce777e8e9;hpb=aa82fa84a083b7b90862f5f4c368f07dd62ae717 diff --git a/week1.mdwn b/week1.mdwn index a5e697a5..cacb73fc 100644 --- a/week1.mdwn +++ b/week1.mdwn @@ -57,18 +57,7 @@ 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 won't *participate* in that convention; we'll probably just say "term" and "expression" indiscriminately for expressions of any of these three forms. - -Examples of expressions: - - x - (y x) - (x x) - (_x y) - (_x x) - (_x (_y x)) - (x (_x x)) - ((_x (x x)) (_x (x x))) +Some authors reserve the term "term" for just variables and abstracts. We won't participate in that convention; we'll probably just say "term" and "expression" indiscriminately for expressions of any of these three forms. 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: