Re: OCL



Date view Thread view Subject view Author view Attachment view

From: Steffen Zschaler (sz9@inf.tu-dresden.de)
Date: Mon 17 Feb 2003 - 13:25:39 GMT


Actually this problem is not related to flattening of collections 
really. Also, in OCL 2.0 -as proposed- collections will not be flattened 
automatically.

I think what you would want to write in OCL in order to correctly 
formalize your constraint is: $rb->forAll (rc = r)$

Regards,

Steffen Zschaler

kcl@dcs.kcl.ac.uk schrieb:

>Flattening of sets seems to lead to a lack of precision -- for 
>example if
>there are many-valued roles $rb$ from class $A$ to
>class $B$ and $rc$ from $B$ to $C$, and $r$ from
>$A$ to $C$, the OCL constraint $rb.rc = r$ does not
>imply that each $b$ in $a.rb$ has $b.rc = a.r$,
>merely that the union of all the $b.rc$ is $a.r$? 
>
>Constraints attached to relations (eg: rc = r on the A_B 
>association) would be needed. 
>
>K. Lano
>
>
>
>To remove yourself from this list please mail puml-list-request@cs.york.ac.uk
>with a message containing the word "unsubscribe".
>  
>

-- 
Dipl.-Inf. Steffen Zschaler
Research Assistant

Dresden University of Technology
Department of Computer Science

Phone +49 351 463 38555
Fax   +49 351 463 38459
Email Steffen.Zschaler@inf.tu-dresden.de

Date view Thread view Subject view Author view Attachment view