Definition and domain axiom of 'member part of' are not equally restrictive

[avsculley]

According to the definition, b is a member part of c means that b is an object and c is a material entity. However, the domain axiom says that its domain is 'material entity.'

[alanruttenberg]

This is a problem having to do with the fact that the children of material entity are not disjoint or rigid. Something that is an object can be an object aggregate at the same time, or at a different time.
Domains and ranges are not temporally indexed, so they effectively have an "all times" interpretation. Since the thing that was an object and therefore member part at some time, might at a later time not be an object (and not be member part at that time), all we can say is that it is for sure a material entity (rigidly).
The domain axiom is not incorrect, it is true. No matter when something instantiates object, it is still the case that if the member part at some time relation holds at some time, the subject is a material entity (which at some time must be an object)

This is a case where the OWL

Please let me know if you are satisfied with the explanation and I can close this issue.

[phismith]

In Alan's view, an object can be an object aggregate at the same time, or at a different time. This is not my view. Thus a multi-celled organism is not identical to an aggregate of cells, because the intercellular space (for example) is also part of the organism. This difference does not, however, affect Alan's conclusion. BS

[alanruttenberg]

Also see #8

[avsculley]

@alanruttenberg @phismith I'm almost satisfied. I wasn't necessarily suggesting that the domain axiom is incorrect. It could be that the definition is incorrect. So given Alan's explanation, why doesn't the definition then read

b is a member part of c means that b is a material entity and c is a material entity....

?

[alanruttenberg]

The definition, before issue #110 was noticed was:

b member part of c at some time =Def for some time t (b is an object & there is at t a mutually exhaustive and pairwise disjoint partition of c into objects x1, ..., xn (for some n ≠ 1) with b = xi (for some 1 <= i <= n))

An appropriate edit to this would be to clarify that "b is an object at t", with similar changes to mentions of object aggregate in the definitions.

This will have to be resolved as part of #110.

[avsculley]

Ok - I'm satisfied if it will be resolved as part of #110. Thanks for the explanations.

…

________________________________ From: Alan Ruttenberg ***@***.***> Sent: Friday, September 27, 2024 6:46 PM To: BFO-ontology/BFO-2020 ***@***.***> Cc: Alec Sculley ***@***.***>; Author ***@***.***> Subject: Re: [BFO-ontology/BFO-2020] Definition and domain axiom of 'member part of' are not equally restrictive (Issue #102) The definition, before issue #110<#110> was noticed was: b member part of c at some time =Def for some time t (b is an object & there is at t a mutually exhaustive and pairwise disjoint partition of c into objects x1, ..., xn (for some n ≠ 1) with b = xi (for some 1 <= i <= n)) An appropriate edit to this would be to clarify that "b is an object at t", with similar changes to mentions of object aggregate in the definitions. This will have to be resolved as part of #110<#110>. — Reply to this email directly, view it on GitHub<#102 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/ATJNTN6S7A34BSXAVCQHPVTZYXN3ZAVCNFSM6AAAAABNWYRIWKVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDGOBQGI2DINBXGY>. You are receiving this because you authored the thread.Message ID: ***@***.***>