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From: Kai Petzke <petz0433@idefix.physik.tu-berlin.de>
Newsgroups: comp.lang.beta
Subject: Re: Redefinition of attributes in BETA (Q)
Date: Fri, 11 Oct 1996 16:07:17 +0200
Organization: Technical University Berlin, Germany
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Bernd Holzmueller wrote:
> E.g., is it allowed to write
> 
>         V: (# A: @Integer; #)
> 
>         W: V (# A: @Real; #)

Yes.  Whenever you access W.A, you will get the Real value,
when you access V.A, you will get the Integer value.

> and does then the W pattern look like
> 
>         (# A: @Integer; A: @Real; #) ?

Yes, except that the first A is inaccessible by direct means.
However, it can be accessed by using a reference to a type,
where the second A has not yet been defined:

     (#
	p1: ^V;
	p2: @W;
     do
	p2.A;	(* accesses the Real value in W *)
	p2[]->p1[];
	p1.A;	(* accesses the Integer value, that is both in
		   V and W *)
     #)


Kai