Logical OR in sequence diagram

Hi,

How can we implement logical OR in sequence diagram?
Scenario: I draw three instances A,B and C. event1 and event2 comes from instance A to instance B, and on receiving any one of these two events instance B has to generate evStart to instance C. So i need to make logical OR among these event1 and event2. pls help me how can i draw this scenario in sequence diagram.

Regards,
Sham.

Hi Sham,

Have you tried using Alternative Combined Fragment? It may be what you are looking for.

Best regards,
Jick

[quote=Jick]Hi Sham,

Have you tried using Alternative Combined Fragment? It may be what you are looking for.

Best regards,
Jick
[/quote]

Hi Jick,

Thanks for your reply.
I’m using UML2.0, so it doesn’t have Alternative Combined Fragment, it has Interaction Operator "Creating Interaction Operators

Interaction operators, which are included in UML 2.0, are used to group related elements in a sequence diagram. This includes the option of defining specific conditions under which each group of elements will occur.
Characteristics of Interaction Operators

Each interaction operator has a type, which determines its behavior, for example Opt, Par, or Loop. In addition, interaction operators can include a guard to specify specific conditions under which the path will be taken. "

And i don’t have any condition to put. B has to generate evStart on receiving either event1 OR event2.

please find the attached sequence diagram and let me know weather it is correct or not.

Thanks,
Sham.
SDE.doc