The class of width-two orders has a model companion. The model companion is complete, decidable, non-finitely axiomatizable, and has continuum many countable models. Generalizations of some results in (Pouzet, M., 1978, J. Combin. Theory Ser. B 25) are presented in the width-n case, for n>2.

second order logic on infinite words is

For a theory T in L, T oe is the theory of the models of T with an automorphism oe. If T is an unstable model complete theory without the independence property, then T oe has no model companion. If T is an unstable model complete theory and T oe has the amalgamation property, then T oe has

by adding axioms asserting that σ is an L-automorphism. The modern study of the model companion of theories with an automorphism has two aspects. One line, stemming from Lascar [7], deals with ‘generic ’ automorphisms of arbitrary structures. A second, beginning with Chatzidakis and Hrushovski [2

This paper surveys locally weighted learning, a form of lazy learning and memorybased learning, and focuses on locally weighted linear regression. The survey discusses distance functions, smoothing parameters, weighting functions, local model structures, regularization of the estimates and bias

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Introduction These notes represent a commentary on a recent preprint of Baldwin and Shelah [?]. The issue (raised for example in [?]) is to find some kind of characterization of when T # has a model companion. Here T is a complete theory with quantifier

SUMMARY In a recent paper, Bai and Perron (1998) considered theoretical issues related to the limiting distribution of estimators and test statistics in the linear model with multiple structural changes. In this companion paper, we consider practical issues for the empirical applications

Using techniques pioneered by R. McKenzie, we prove that there is no algorithm which, given a finite algebra in a finite language, determines whether the variety (equational class) generated by the algebra has a model companion. In particular, there exists a finite algebra such that the variety

Abstract not found