From: Jim Pryor Date: Sat, 16 Oct 2010 18:13:35 +0000 (-0400) Subject: alternate Y1,Y2 tweak X-Git-Url: http://lambda.jimpryor.net/git/gitweb.cgi?p=lambda.git;a=commitdiff_plain;h=7c8829dbea0cfaa2fedfb7d6fdd46d1558e9e68a alternate Y1,Y2 tweak Signed-off-by: Jim Pryor --- diff --git a/hints/assignment_4_hint_3_alternate_1.mdwn b/hints/assignment_4_hint_3_alternate_1.mdwn index 12ddbd6b..c62d620d 100644 --- a/hints/assignment_4_hint_3_alternate_1.mdwn +++ b/hints/assignment_4_hint_3_alternate_1.mdwn @@ -9,15 +9,15 @@ Alternate strategy for Y1, Y2 in C -is implemented using regular, non-mutual recursion, like this (`f'` is a variable not occurring free in `A`, `B`, or `C`): +is implemented using regular, non-mutual recursion, like this (`u` is a variable not occurring free in `A`, `B`, or `C`): - let rec f' g x = (let f = f' g in A) - in let rec g y = (let f = f' g in B) - in let f = f' g in C + let rec u g x = (let f = u g in A) + in let rec g y = (let f = u g in B) + in let f = u g in C or, expanded into the form we've been working with: - let f' = Y (\f' g x. (\f. A) (f' g)) in - let g = Y (\g y. (\f. B) (f' g)) in - let f = f' g + let u = Y (\u g x. (\f. A) (u g)) in + let g = Y (\g y. (\f. B) (u g)) in + let f = u g