[ASN.1] ValueSet question

[Avin Patel]

Hi,
I have couple of questions regarding ValueSet definition.

1)
According to Debusion book, page 335, clause (15). ValueSet should have
atleast one common value with parent type. While in TCAPMessage.asn(X.880)
file, I have found following definition:

Component{OPERATION:Invokable, OPERATION:Returnable} ::= CHOICE {
  basicROS             ROS{{TCInvokeIdSet}, {Invokable}, {Returnable}},
  returnResultNotLast
    [7]  returnResult < ROS{{TCInvokeIdSet}, {Invokable}, {Returnable}}
}

TCInvokeIdSet ::= InvokeId(WITH COMPONENTS {
                             present  (-128..127)
                           })

As TCInvokeIdSet is not ValueSetAssignment & is a TypeAssignment, Here
TCInvokeIdSet doesn't represent common value with parent type InvokeId.

2)
Is ValueSet means It can have only Values as ElementSetSpecs or It can also
be Types.

Is following definition is correct?
TypeA ::= INEGER
ValueSetA TypeA ::=  { TypeA (123 .. 125) }

Here "TypeA(123 ..125) is" Type, not a Value.

3)
Can ValueSet have DefinedType in ElementSetSpecs?

4)
If I compare ValueSet with ObjectSet.
ObjectSet can have only InformationObjects. So ValueSet should have only
Values. Is it correct.
Or
ValueSet can have Values & Types, While ObjectSet can have only
InformationObject, but can't have CLASS.

Thank you for your time,
Avin Patel