A few weeks ago I posted a question about a problem related to the arguments of messages in this forum (http://www.eclipse.org/forums/index.php/m/1062312/#msg_1062312 [1]). Unfortunately, nobody replayed with an answer to my problem.

Let's assume a sequence diagram describing an interaction between two objects, namely objA, of class ClassA, and object objB, of class ClassB. Class ClassB offers an operation called anOperation with a parameter of type Boolean. During the interaction, objA sends to objB a synchronous call message to invoke the operation anOperation.

When I try to add to the message an argument of type Boolean to match the operation anOperation signature, Papyrus only allows me to add a LiteralBoolean with values true or false. I would like to write an arbitrary expression of type Boolean, e.g. self.attribA.oclIsUndefined(), but Papyrus doesn't allow me so. However, the UML 2 superstructure metamodel, as defined in the OMG specification, allows to add a value of type OpaqueExpression, that could be the previous OCL expression.

I don't want to write only a literal, but OCL expressions too. Does someone know any way to do it in Papyrus? Does someone know if this situation is a limitation of Papyrus or if I'm misunderstanding the UML metamodel?

Warning	The signature of message model::Class3::Interaction1::1:Operation1_Message is an operation but the arguments of the message do not correspond to the parameters of the operation. 	<Message> 1:Operation1_Message	model::Class3::Interaction1	EMF Problem