This chapter raises the following question: Who is right, the logician or the mysterian? Not the logician, it seems, for her recipe does not work; B→A is a terrible candidate for the role of A–B. No recipe could work, one might think, for we know of cases where B cannot be cleanly excised from A. What is the remainder supposed to be when Tom is red is subtracted from Tom is crimson, or Tom is red or green is subtracted from Tom is red? Not the mysterian either, for she thinks that a recipe is impossible, and we have attempted to give one. That being said, the logician is right, insofar as a remainder always exists. And the mysterian is right, insofar as A–B may not extend very far out of the Bregion. Possible applications include analysis from above, metaontology, and epistemic modality.