- From: Provenance Working Group Issue Tracker <sysbot+tracker@w3.org>
- Date: Fri, 29 Jul 2011 09:01:11 +0000
- To: public-prov-wg@w3.org
PROV-ISSUE-56 (derivation-definition-does-not-imply-transitivity): Derivation as defined is not transitive [Conceptual Model] http://www.w3.org/2011/prov/track/issues/56 Raised by: Graham Klyne On product: Conceptual Model [[ Given an assertion isDerivedFrom(B,A), one can infer that the use of characterized entity denoted by A precedes the generation of the characterized entity denoted by B. ]] Where does this notion of "use" come from in the absence of some referenced activity? Concerning transitivity of derivation: Suppose: A has attributes a0, a1 B having attributes b0, b1 is derived from A, with b0 being dependent on a0 C having attributes c0, c1, is derived from B with c1 being dependent on b1 So none of the attributes of C can be said to be directly or indirectly dependent on attributes of A, which by the given definition is a requirement for derivation of C from A. Thus, as defined, derivation cannot be transitive. I don't really know if derivation should or should not be transitive, but the above seems to me like a problem of spurious over-specification. My suggestion for now would be to focus on what really matters and see what logical properties fall out later.
Received on Friday, 29 July 2011 09:01:16 UTC