QVT — Missing variable references within inlined object expressions

Inlined ObjectExp have no explicit result variable. Nevertheless
An implicit variable is needed so that the representation of property
access within the body of ObjectExp is consistent.
These variables need to exist somewhere and so a container for these
implicit variables is needed.

Suggestion:
Adding the association:
OperationBody::variable : [*] Variable

And make the multiplicity of ObjectExp::referredObject equal to '1'

(1) In Section 8.2.1.17 (OperationBody), add the association
"""
variable : [*] Variable

The variables defined implicitly within this operation body.
This concerns implicit variables in object expressions (ObjectExp).
"""
(2) In Section 8.2.1.24, replace "referredObject: Variable [0..1]"
by "referredObject: Variable [1]"
(3) In figure 8.2 add the "OperationBody::variable Variable" unidirectional
link
(4) In figure 8.3 change multiplicity of ObjectExp::referredObject to '1'.