Re: Idempotence and "Replication Insensitivity" are equivalent ?
Date: 20 Sep 2006 20:26:55 -0700
Message-ID: <1158809215.893335.141530_at_m73g2000cwd.googlegroups.com>
William Hughes wrote:
>
> This is silly. I have a function f:A,A->A, but this is
> too restrictive so I will change this to a function f:A,B->B,
> but now I want to talk about idempotence so I will
> let A=B, so I have a function f:A,A->A but this is
> too restrictive so ...
I have no idea what you're trying to say here.
Anyway, A, B -> B as the most general type of a the first argument to fold is not my formulation; it's been around for a long time. I would prove that with a Google search, but alas! Google throws away most punctuation, and the first hit for "A, B -> B" is "The Official BB King Website."
> Have I got this straight.
>
> S can contain an arbitrary number of elements of A,
> so f(a,S) takes an arbitrary number of elements of A, but
> f is despite this a binary form?
No; I wouldn't call it binary unless A = B. But is this question really important? Boy you are really hung up on nomenclature. :-)
Marshall Received on Thu Sep 21 2006 - 05:26:55 CEST