I.e. the "novel" is the process of negotiation and conflict between competing ideologies, rather than a definable and fixed set of thematic or generic conventions.

The method of quantifier elimination can be used to show that definable sets in particular theories cannot be too complicated.

In the case of RCF, the definable sets are the semialgebraic sets.

Since we have a definable set that isn't a finite union of points and intervals, this structure is not o-minimal.

A definable set.

To see that it is an interpretation (without parameters), one needs to check the following preimages of definable sets in Q:

Ordinal definable sets were introduced by .

The sets definable in this structure are known as the arithmetical sets, and are classified in the arithmetical hierarchy.

An important result about definable sets is that they are preserved under automorphisms.

What can be expressed is that any definable set of natural numbers has this property.