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Re: another operation
| Date: Sun, 9 Jan 2005 02:31:52 -0800 (PST)
| From: bear <bear@xxxxxxxxx>
| On Sun, 9 Jan 2005, Aubrey Jaffer wrote:
| > | From: sebastian.egner@xxxxxxxxxxx
| > | 2. When scanning different libraries of bit-twiddling, I had
| > | stumbled across an implicit design decision that is worth
| > | mentioning because it might swiftly break portability's neck:
| > |
| > | "What is the value of (LOGAND)?"
| > |
| > | In my application I define (LOGAND) := 0 because the subsets my
| >(logand) ==> -1 because (and) ==> #t.
| >This is also necessitated because logand is associative:
| >(logand a b) == (logand a (logand b) (logand))
| I do not understand why (logand) with zero arguments
| ought not signal an error. Can you enlighten me?
When dealing with variable arity, empty lists can happen.