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Unintended models/not intended/interpretation/Simons: arise e.g. when one axioms a modal term non-modally. - analog: if one interprets a mereological term topologically because topologically all quantities exist (closed as open). - Modal/non-modal/(s): non-modal: do then exist necessary as well as non-technical terms equally (indistinguishable). - Solution/Simons: We can embed a non-modal theory in a modal. - Problem: the modalized theory cannot deal then with facts and actual existence.
To connect mathematics and world, you need the relations of modal and non-modal truths.
Parts Oxford New York 1987