Re: OCL question

Re: OCL question

From: Humberto Castejon <>
Date: Sat, 23 Feb 2008 12:58:12 +0100
Message-ID: <>
Hi again!

I attach a diagram that may help to better understand my question.


Humberto Castejon wrote:
> Hi!
> I have some problems using OCL together with collaborations and 
> collaboration uses. I would be very grateful if you oculd help me with 
> the following.
> Imagine we have a Sale collaboration with two roles: buyer and seller. 
> Now, by means of a collaboration use, we bind both roles to the same 
> classifier, namely Person. An instance of Person may then behave either 
> as a seller or as a buyer in a Sale collaboration. However, we do not 
> want the same instance of Person to play both the seller and the buyer 
> roles in the same occurrence of a Sale collaboration (i.e. we do not 
> want a person to sell to herself).
> Would the following OCL invariant, specified in the context of the 
> collaboration use, be correct?
> Context s:Sale
> inv s.roleBinding->forAll(b1, b2 | b1.client.allInstances->forall(Person 
> p1 | b2.client.allInstances->forall(Person p2 | p1 <> p2)))
> Thanks for you help!
> Cheers,
> Humberto

Received on Sat 23 Feb 2008 - 11:57:59 GMT