RegistryQuery query

[Tony Linde]

Isn't it usual that NOT is a unary operator which reverses the boolean value
of an operand and NOT_EQUAL (<> or !=) is a binary operator with the usual
meaning(s).

Cheers,
Tony. 

> -----Original Message-----
> From: owner-registry at eso.org [mailto:owner-registry at eso.org] 
> On Behalf Of Matthew Graham
> Sent: 08 June 2004 21:55
> To: Tony Linde
> Cc: registry at ivoa.net
> Subject: RegistryQuery query
> 
> 
> Hi,
> 
> I have been looking at the QueryResource schema and was 
> wondering about the "not" operand - is it supposed to be an 
> existence operator or test whether a particular ResourceXPath 
> is true or false? In either case the proposed syntax strikes 
> me as being rather like Reverse Polish:
> 
> <ResourceXPath> not 
> 
> or
> 
> <ResourceXPath> not <value = true/false?>
> 
> Is it actually supposed to be the <does-not-equal> operator, 
> in which case can it be renamed to that?
> 
> 	Cheers,
> 
> 	Matthew
>