Re: Help...Current status of formalization of UML



Re: Help...Current status of formalization of UML

From: Pierre-Yves Schobbens ^lt;pys@info.fundp.ac.be>
Date: Mon 01 May 2006 - 20:56:04 BST
Message-Id: <4B8646C5-1030-4BE2-BBFB-0D86CAC9F107@info.fundp.ac.be>
Le 30-avr.-06 à 13:02, Arend Rensink a écrit :

> Pierre-Yves Schobbens wrote:
>
>> 2- A transformation, by definition, cannot be a semantics.
>>    Transformations are by definition executable, while semantics  
>> concepts for UML are not decidable.
>>    Thus this is impossible to define semantics with  
>> transformations alone: we need more powerful tools.
>
> I don't understand this statement.

Yes, it boils down to vocabulary, that I should have defined in the  
first place -- apologies!

> A natural way to use GT as a tool to define semantics would be to  
> give a small-step operational semantics on the basis of graph  
> transformation rules. The semantics is then the outcome of a  
> computation consisting of a sequence of such small steps, which is  
> as undecidable as you could ever wish it to be.

1- I don't call this a transformation, since I use this word in the  
MDA sense, so it operates on UML models, not on states.

2- To my mind, small-step semantics must be completed by a refinement  
ordering (e.g. simulation). This ordering can then serve as a basis  
for (justified) transformations (of UML models).
Received on Mon May 01 20:55:59 2006