[Data-modeling] [data-modeling] "Subtypes" and Delegated Properties

[Vishal Talwar]

Hello data modelers,
So in Freebase, rather than a system of type inheritance, we use
mixins/included types. We don't really create subtypes, we really create
overlay types, which include the parent type and any extra properties or
types. The issue I am running into is how to make this interacts favorably
with delegated properties. If I understand them correctly (this is pretty
questionable), delegated properties are a way of reusing properties so that
data is added to old types/properties under the guise of new ones. The
situation is as follows:

Types A and B are in some base
Type A includes Fictional Setting
Type B includes Fictional Work

Fictional Setting links to Fictional Work via the Fictional Works Set
Hereproperty
Fictional Work reciprocates this link via the Setting property

I want this connection to hold (and display) for my types as well, so the
obvious thing is to connect A and B by delegating to those properties. The
problem is that you also inherit the expected type, which would be Fictional
Setting or Fictional Work, but not A or B, despite the fact that they
include the former. I could instead go and create a new property specific to
A and B (i.e. with them as the expected types), but it would be redundant
and I'd be including the commons types but not adding any useful information
to them. Does anyone have any advice? Am I missing something really obvious?

Thanks,
Vishal
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