One substance, more than one place

The same substance is published in two contexts that are two different places, rather than one place described at two levels of detail — each of them states something the other denies. Where a substance is *released* is a fact about the process, so releases are not compared here: a metal emitted to air and to a river is two ordinary flows. Where it is *taken from* is a fact about the substance. Peat comes out of the ground, wood off a living tree, geothermal heat out of the rock beneath, and no process chooses — so two of those on one substance are two answers to a question that has one, and one of them was written by the merge on behalf of a source list that files the substance elsewhere. Nothing goes wrong at any single step, which is why this needed a check: the two halves are separate identifiers that can never meet, so an inventory using one and a method characterising the other simply do not connect. `Units` says whether the two even measure the same thing. Answering means deciding which place is right and writing it down — a rule in `context-manual-mapping.json` when the source list filed the row in the wrong compartment, or a target in that list's match overrides when it meant a different substance. Leaving it is also an answer, and it is the one that keeps two flows.

substance-in-two-places