Permanent generic parthood desired

From alanruttenberg@gmail.com on June 15, 2012 13:22:51

The current ternary relations

r-at-all-times r-at-some-times

express permanent-specific relations.

...

Being so, the pattern that has been termed as "Permanent relatedness" = at any time there is some instance of B related by r. (e.g. all cells contain some triglyceride) can only be expressed by the relation r-at-some-times (because it is not always the same triglyceride molecule).

The relation r-at-all-times would then only be used for the stricter case ("permanent specific relatedness") where there is not only always a relation to some instance of the same type, but always to the same entity (e.g. all cells contain some membrane - always the same)

The problem I see then is that r-at-some-time is never transitive, even if r is. Example: "has-part-at-some-times"

How do I get the following inference in OWL:

At any time all cells have some triglyceride molecule as part
At any time all triglyceride molecules have some fatty acid residue as part ==> At any time all cells have some fatty acid residues as part

We cannot use the (transitive) relation "has-part-at-all-times" here, due to the fact that the molecules are not permanently part of a cell.
Using the non-transitive relation "has-part-at-some-times" I don't get the inference I need.

Original issue: http://code.google.com/p/bfo/issues/detail?id=54

BFO-ontology / BFO

Permanent generic parthood desired #54