===========
CoacIsOnBfd
===========
.. rubric:: Description


This modelling pattern allows to express that a 
‘class of activity’ is referred to on a document that is a BFD 
(block flow diagram). No information about the type of reference is made -
it could be symbolic, textual or both.
It is assumed that, while parsing the information about the COAC from a 
data file, an entity for the underlying document can be found or is created
in a database that contains information about documents.


.. rubric:: Definition


A class of activity is referenced on a document of type Block Flow Diagram.


.. image:: CoacIsOnBfd.svg


::

    
    CoacIsOnBfd(x1, x2) <-> 
        ClassOfActivity(x1) & 
        ClassOfInformationObject(x2) & 
        MMT:ReferenceToClassOfIndividualOnDocument(x1, x2) .
    

.. rubric:: Roles

1. hasCoac

2. hasOnBfd

.. rubric:: Restrictions

* Role filler of hasCoac must have entity type ClassOfActivity.

* Role filler of hasOnBfd must have entity type ClassOfInformationObject.

* One of:

  * Role filler of hasOnBfd must be a specialization of Document.

  * Role filler of hasOnBfd must be used as the role filler of hasThis with respect to the :doc:`../ThisIsADocument/index` pattern.

* One of:

  * Role filler of hasOnBfd must be a specialization of BlockDiagram.

  * Role filler of hasOnBfd must be used as the role filler of hasDocument with respect to the :doc:`../DocumentIsOfDocumentClass/index` pattern.