|Actual: in relation to the real world as opposed to a merely possible world or situation.|
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Modal operator / problem of actuality/ Field: E.g. it is possible that a distance is twice or half as large as it actually is. - This can not be done by the possibility operator alone. - Wrong solution: "actuality operator": which is to refer to the actual world. - Modality: is used by the relationism to mean that a doubled distance is possible, even if there is no matter point there. - Substantivalism does not need that.
Realism, Mathematics and Modality Oxford New York 1989
Truth and the Absence of Fact Oxford New York 2001
Science without numbers Princeton New Jersey 1980