From fd6b36c3552b1b3c7d0d2eb497b3c925cab9418f Mon Sep 17 00:00:00 2001 From: jim Date: Mon, 23 Feb 2015 14:22:23 -0500 Subject: [PATCH] add note about generalization --- exercises/assignment3_answers.mdwn | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/exercises/assignment3_answers.mdwn b/exercises/assignment3_answers.mdwn index 6aa5d750..ea0256da 100644 --- a/exercises/assignment3_answers.mdwn +++ b/exercises/assignment3_answers.mdwn @@ -267,6 +267,12 @@ S (S (KS) (S (KK) (S (KS) K))) (KI); this is the B combinator, whi 25. For each of the above translations, how many `I`s are there? Give a rule for describing what each `I` corresponds to in the original lambda term. + This generalization depends on you omitting the translation rule: + + 6. @a(Xa) = X if a is not in X + + > With that shortcut rule omitted, then there turn out to be one `I` in the result corresponding to each occurrence of a bound variable in the original term. + Evaluation strategies in Combinatory Logic ------------------------------------------ -- 2.11.0