|Sets: a set is a summary of objects relating to a property. In the set theory, conditions are established for the formation of sets. In general, sets of numbers are considered. Everyday objects as elements of sets are special cases and are called primordial elements. Sets are, in contrast to e.g. sequences not ordered, i.e. no order is specified for the consideration of the elements. See also element relation, sub-sets, set theory, axioms.|
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Class/set/ / Prior: the statement that something is a member of a class is only seemingly a sentence about classes - in reality it is nothing more and nothing less than to say that "x f-s". - the appearance of the existence of "x" and of the existence of classes disappears - Clases are only logical construtions - only then the identity of unicorns and Pegasi is harmless (via the empty set) -
Logical constructions are no entities: all classes are logical constructions.
Objects of thought Oxford 1971
Arthur N. Prior
Papers on Time and Tense 2nd Edition Oxford 2003