The two PRESENTATION columns every contract declares — what kind of control carries the fact,
and where its travel comes from. Any contract's declaration is assignable to this, which is
what lets one provenance rule serve all of them instead of each table growing its own.
The two PRESENTATION columns every contract declares — what kind of control carries the fact, and where its travel comes from. Any contract's declaration is assignable to this, which is what lets one provenance rule serve all of them instead of each table growing its own.