Yes, this is in theory possible depending on how you use this library!
I've seen this done as CVTs (Compound Value Types).  To take your example,
(Joe HAS employee status) SINCE 2012-10-28, it'd be something like:

Subject: Joe
Predicate: /employment/status
Object: "6988a214-368c-40a2-9e51-8a7f5549de44"

Subject: "6988a214-368c-40a2-9e51-8a7f5549de44"
Predicate: /employment/start
Object: "2012-10-28"


On Thu, Oct 27, 2022 at 7:39 PM Jean Louis <bugs@gnu.support> wrote:

> I have forgot to mention that any relationship subject, predicate,
> object, itself, should be capable of becoming both subject and object.
>
> Employee IS status
> Joe HAS employee (status)
> Date IS TIME, etc.
> 2012-10-28 IS date
> (Joe HAS employee status) SINCE 2012-10-28
> ABC INC. IS company
> Company EMPLOYED Joe
> Trevis HAS manager (status)
> (Company EMPLOYED Joe) HAS Trevis
> ((Company EMPLOYED Joe) HAS Trevis) MANAGES Joe
>
> and so on
>
>
> --
> Jean
>
> Take action in Free Software Foundation campaigns:
> https://www.fsf.org/campaigns
>
> In support of Richard M. Stallman
> https://stallmansupport.org/
>