Re: NULLs: theoretical problems?
From: Jon Heggland <jon.heggland_at_idi.ntnu.no>
Date: Mon, 03 Sep 2007 08:21:02 +0200
Message-ID: <fbg94r$7rd$1_at_orkan.itea.ntnu.no>
>
> I'm not so sure what you mean by "check". Any proposition in
> IMPS is FALSE if any of its arguments is undefined. So as an
> example (x OR TRUE) is false if x is NULL. Does this suffice
> for what you mean by "check"?
Date: Mon, 03 Sep 2007 08:21:02 +0200
Message-ID: <fbg94r$7rd$1_at_orkan.itea.ntnu.no>
Quoth Keith H Duggar:
> Jon Heggland wrote:
>> In this system, how can you check whether a given variable actually is >> NULL or not?
>
> I'm not so sure what you mean by "check". Any proposition in
> IMPS is FALSE if any of its arguments is undefined. So as an
> example (x OR TRUE) is false if x is NULL. Does this suffice
> for what you mean by "check"?
Yes, thank you.
-- JonReceived on Mon Sep 03 2007 - 08:21:02 CEST