SYSML16 — Copy constraints #2 and #3 shoud be merged together

Copy constraint#2 states:

The text property of the client requirement is constrained to be a read-only copy of the text property of the supplier requirement.

While Copy constraint#3 states:

Constraint [2] is applied recursively to all subrequirements.

They should be merged in one unique constraint so that the requested recursivity could be formally stated in OCL using an helper operation

Merged with SysML16-274

To be fixed as part of SYSML16-311

• Add an "Operations" sub clause with the following operation definition:
  isCopy (in req1 : AbstractRequirement, in req2 : AbstractRequirement) : Boolean [1]

bodyCondition:
let subReq1: Set(AbstractRequirement) = AbstractRequirement.allInstances()->select(r | req1.base_NamedElement.ownedElement->includes(r.base_NamedElement)) in
let subReq2: Set(AbstractRequirement) = AbstractRequirement.allInstances()->select(r | req2.base_NamedElement.ownedElement->includes(r.base_NamedElement)) in
req1.text = req2.text and
subReq1->size() = subReq2->size() and
subReq1->forAll(r1 | subReq2->exists(r2 | self.isCopy(r1, r2) ))

• Constraint#2's textual statement shall be replaced by:
  The text property of the client requirement is constrained to be a read-only copy of the text property of the supplier requirement and this applies recursively to all subrequirements (i.e. requirements related by a containement relationship)

• Constraint#2's OCL statement shall be:

  let cltReq: AbstractRequirement = AbstractRequirement.allInstances()->any(r | self.base_Abstraction.client->includes(r.base_NamedElement)) in
  let supReq: AbstractRequirement = AbstractRequirement.allInstances()->any(r | self.base_Abstraction.supplier->includes(r.base_NamedElement)) in
  self.isCopy(cltReq, supReq)
  

• Constrain#3 shall be deleted