Re: Defining required object properties given that a different object property is true.

On 1 Dec 2010, at 23:20, Mitchell Gillespie wrote:

> Hi All,
>
>    Let's consider this simple example (excusing my notation).   
> Class:Person requires the following rule when refering to  
> Class:TwinType.    This is not my actual context, I am simply  
> looking for the proper methodology to define this restriction/rule..
>
> IF (<individual_Pers1>  hasTwinType  <individual_FaternalTwins) THEN
>         THIS MUST BE TRUE  (<individual_Pers1> hasSon Class:Person)   
> AND ( <individual_Pers1> hasDaughter Class:Person)
>
>   Essentially, I want to specify that if a Person has Twins then  
> that person must also hasSon AND hasDaughter.  Obviously, this  
> example isn't true in reality, but I need to define that given that  
> an individual of Class:Person has an object property to a specific  
> individual THEN  that given individual of Class:Person must also  
> satisfy two other object property relationships...
>
>   I am using OWL2 in Protege 4.1.  Any suggestions on how this is  
> defined in the Equivalent Class definitions?
>

Hi Mitchell,

as this is an implication, "if", (and not a bi-implication, "if and  
only if"), a subclass axiom will do the trick: you want to make

hasTwinType some FaternalTwins SubClassOf ((hasSon some Person) and  
(hasDaughter some Person))

...you can do this (i.e., adding a subclassaxiom where the left hand  
side is a complex class expression and not only a class name) in the  
"general axioms" pane in the "active ontology" part.

Cheers, Uli


> Thanks!!
>
> -- 
> Mitchell Gillespie
> MSc. Applied Computer Science
> University of Guelph
> mgillesp@uoguelph..ca
> Cell:  (416) 433-8931
>
>