From 87483b8ff52adf85fd8d80060427f9e67f698b8a Mon Sep 17 00:00:00 2001 From: Jim Pryor Date: Wed, 15 Sep 2010 17:21:42 -0400 Subject: [PATCH] week1 tweaks Signed-off-by: Jim Pryor --- week1.mdwn | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/week1.mdwn b/week1.mdwn index 5c880fbb..c68da8a0 100644 --- a/week1.mdwn +++ b/week1.mdwn @@ -224,11 +224,11 @@ Shorthand The grammar we gave for the lambda calculus leads to some verbosity. There are several informal conventions in widespread use, which enable the language to be written more compactly. (If you like, you could instead articulate a formal grammar which incorporates these additional conventions. Instead of showing it to you, we'll leave it as an exercise for those so inclined.) -Dot notation: dot means "put a left paren here, and put the right +**Dot notation** Dot means "put a left paren here, and put the right paren as far the right as possible without creating unbalanced parentheses". So: - (\x (\y (xy))) + (\x (\y (x y))) can be abbreviated as: @@ -236,23 +236,23 @@ can be abbreviated as: and: - (\x \y. (z y) z) + (\x (\y. (z y) z)) would abbreviate: - (\x \y ((z y) z)) + (\x (\y ((z y) z))) This on the other hand: - ((\x \y. (z y) z) + (\x (\y. z y) z) would abbreviate: - ((\x (\y (z y))) z) + (\x (\y (z y)) z) -Parentheses: outermost parentheses around applications can be dropped. Moreover, applications will associate to the left, so `M N P` will be understood as `((M N) P)`. Finally, you can drop parentheses around abstracts, but not when they're part of an application. So you can abbreviate: +**Parentheses** Outermost parentheses around applications can be dropped. Moreover, applications will associate to the left, so `M N P` will be understood as `((M N) P)`. Finally, you can drop parentheses around abstracts, but not when they're part of an application. So you can abbreviate: - (\x x y) + (\x. x y) as: @@ -266,7 +266,7 @@ and: z (\x. x y) -Merging lambdas: an expression of the form `(\x (\y M))`, or equivalently, `(\x. \y. M)`, can be abbreviated as: +**Merging lambdas** An expression of the form `(\x (\y M))`, or equivalently, `(\x. \y. M)`, can be abbreviated as: (\x y. M) -- 2.11.0