English

Characterizing decidability in a quasianalytic setting

Logic 2010-08-18 v1 Algebraic Geometry

Abstract

Let \RRS\RR_S denote the expansion of the real ordered field by a family of real-valued functions SS, where each function in SS is defined on a compact box and is a member of some quasianalytic class which is closed under the operations of function composition, division by variables, and implicitly defined functions. It is shown that the first order theory of \RRS\RR_S is decidable if and only if two oracles, called the approximation and precision oracles for SS, are decidable. Loosely stated, the approximation oracle for SS allows one to approximate any partial derivative of any function in SS to within any given error, and the precision oracle for SS allows one to decide when a manifold M\RRnM\subseteq\RR^n is contained in a coordinate hyperplane {x\RRn:xi=0}\{x\in\RR^n : x_i = 0\} when one is given i{1,,n}i\in\{1,\ldots,n\} and a system of equations which defines MM nonsingularly, where the functions occurring in the equations are rational polynomials of the coordinate variables x=(x1,,xn)x = (x_1,\ldots,x_n) and the partial derivatives of the functions in SS. A key component of the proof is the development of a local resolution of singularities procedure which is effective in the approximation and precision oracles for §\S, and in the course of proving our main theorem, numerous theorems about the model theory of such structures \RRS\RR_S are also proven.

Keywords

Cite

@article{arxiv.1008.2789,
  title  = {Characterizing decidability in a quasianalytic setting},
  author = {Daniel J. Miller},
  journal= {arXiv preprint arXiv:1008.2789},
  year   = {2010}
}
R2 v1 2026-06-21T16:01:38.821Z