Re: Domain dependence
From: V.J. Kumar <vjkmail_at_gmail.com>
Date: Wed, 20 Jun 2007 00:40:54 +0200 (CEST)
Message-ID: <Xns9954BE0B8765Bvdghher_at_194.177.96.26>
>
> There is some mystery about domain (in)dependence. In this case it was
> such a nice expression
>
> {(x,z)| forall y : A(x,y) <-> B(y,z) }
>
> And now it is ugly.
Date: Wed, 20 Jun 2007 00:40:54 +0200 (CEST)
Message-ID: <Xns9954BE0B8765Bvdghher_at_194.177.96.26>
[posted and mailed]
Vadim Tropashko <vadimtro_invalid_at_yahoo.com> wrote in news:1182291590.251299.251930_at_q19g2000prn.googlegroups.com:
> On Jun 19, 2:58 pm, "V.J. Kumar" <vjkm..._at_gmail.com> wrote:
>> > {(x,z)| (exists y: A(x,y) & exists y: B(y,z) -> forall y : A(x,y)
>> > <-> B(y,z) }
>>
>> Ditto.
>
> There is some mystery about domain (in)dependence. In this case it was
> such a nice expression
>
> {(x,z)| forall y : A(x,y) <-> B(y,z) }
>
> And now it is ugly.
That the problem with first-order logic -- it becomes ugly when you try to express something interesting. English rulez. Received on Wed Jun 20 2007 - 00:40:54 CEST