[protege-discussion] Odd ontology? Your feedback is appreciated

[Thomas Russ]

On Sep 19, 2008, at 1:19 PM, Naji Mouawad wrote:

> Greetings,
>   I have the following class hierarchy (Ontology included below)
>
>     -Applications
>        -Named_Applications
>            -App_1
>        -Business_Apps
>     -Users
>        -Named_Users
>           -User_1
>        -Business_Users
>     and a property: IsBusinessUser which has an inverse proprety:  
> ServicesBusinessUsers.
>
>   App_1:
>       -Application
>       -ServicesBusinessUsers some User_1
>
>    Business_Apps has two necessary and sufficient conditions:
>          -Applications
>          -ServicesBusinessUsers some Named_Users
>
>   User_1:
>          -Applications

Looks like something is missing here.  Or do you mean to say that  
User_1 is a subclass of Applications?

>
>   Business_Users has two necessary and sufficiet conditions:
>          -Users
>          -IsBusinessUser some Named_Apps
>
>  When I run 'classify taxonomy' Apps_1 shows correctly under  
> Business_Apps but User_1 does not show up under Business_Users. I  
> would have expected the reasoner to infer that since
>     -App_1 ServicesBusinessUsers User_1,
>     -ServicesBusinessUser is the inverse of IsBusinessUser, and
>     -Business_users has as a necessray and sufficient condition  
> IsBusinessUsers some Named_Apps
> then it follows that User_1 satisfies the conditions of  
> IsBusinessUser and should show up beneath Business_Users but such is  
> not the case.

No, it does not follow.

You are confusing existential and universal quantification in the  
restriction.

Just because All App_1 instances services SOME instance of User_1, it  
doesn't mean that ALL instances of User_1 use some instance of App_1.