.. _section-Annotation using the description property:

Annotation using the description property
-----------------------------------------

For rules, it is also possible to add a manual paraphrase to the rule label by making use of the ’description’ property. For example, we can add a manual paraphrase to the rule Ancestor\_Rec as follows:

.. code-block:: flora

   @!{AncestorRule_Rec [
     description -> "A person's parent's ancestor is the person's ancestor"^^\string ] }
     ?Person [ancestor -> ?Ancestor ] :-
       ?Person [parent -> ?Parent],
       ?Parent [ancestor -> ?Ancestor].

Now execute the query ’Who are Louisas ancestors?’. Click the question mark next to the returned result **Aaron** to display its explanation tree. Then click to highlight the top branch **Louisa [ancestor -> Aaron]** of the explanation tree. Select **Show Manual Paraphrase** from the right-click menu, as shown in :numref:`figure-NL-ancestor-rule-show-manual-paraphrase.png`.

.. _figure-NL-ancestor-rule-show-manual-paraphrase.png:

.. figure:: ../figs/NL-ancestor-rule-show-manual-paraphrase.png
   :alt: Select **Show Manual Paraphrase** for rule Ancestor\_Rec

   Select **Show Manual Paraphrase** for rule Ancestor\_Rec

A window pops up showing the manual paraphrase of the rule as described by the rule’s description property, as shown in :numref:`figure-NL-manual-paraphrase.png`.

.. _figure-NL-manual-paraphrase.png:

.. figure:: ../figs/NL-manual-paraphrase.png
   :alt: The description property of Ancestor\_Rec is used to manually paraphrase the rule

   The description property of Ancestor\_Rec is used to manually paraphrase the rule

For a rule which has no description property, the **Show Manual Paraphrase** pop-up window will say there is no manual paraphrase available for the rule. For example, the rule ParentRule in family.flr has no description property.

.. code-block:: flora

   @!{ParentRule}
   ?Person [parent -> ?Parent] :-
       ?Parent [child -> ?Person].

If we drill down on **Louisa [ancestor -> Aaron]** in the explanation tree, we will see ParentRule used in establishing the sub-branch **Louisa [parent -> Greg]**. Do **Show Manual Paraphrase** on this rule will pop up a window saying there is no manual paraphrase for the rule available, as shown in :numref:`figure-NL-no-manual-paraphrase.png`.

.. _figure-NL-no-manual-paraphrase.png:

.. figure:: ../figs/NL-no-manual-paraphrase.png
   :alt: Manual paraphrase not available for rule ParentRule

   Manual paraphrase not available for rule ParentRule