How do you validate a reified trace of digital-object provenance?

Rory Macneil nails it:1 This seems to me to be a really important problem.

Given a representation of (meta)data that dcterms:conformsTo some data profile, you may wish to translate it to another data profile.

To validate is to compute, so indexing metadata for past validation events and caching any detailed payloads can save time and effort.