منابع مشابه
Simple structures axiomatized by almost sure theories
In this article we give a classi cation of the binary, simple, ω−categorical structures with SU−rank 1 and trivial pregeometry. This is done both by showing that they satisfy certain extension properties, but also by noting that they may be approximated by the almost sure theory of some sets of nite structures equipped with a probability measure. This study give results about general almost sur...
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In Hill [11], it was shown that an almost-sure theory for a Fraïssé class K relative to an asymptotic probability measure with “independent sampling” is necessarily super-simple of finite rank with D(x=x) = 1. In this note, we show that this independent sampling hypothesis is much stronger than necessary. By examining the Aldous-Hoover-Kallenberg (AHK) presentation of an asymptotic probability ...
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We give an explicit AE-axiomatization of the almost sure theories of sparse random graphs G(n, n−α) of Shelah-Spencer. In the process we give a method of constructing extensions of graphs whose ‘relative dimension’ is negative, but arbitrarily small. We describe the existentially closed and locally finite models of the theory and produce types of dimension zero. We offer a useful characterizati...
متن کاملRandom unary predicates: Almost sure theories and countable models
Let Un,p be the random unary predicate and Tk the almost sure first-order theory of Un,p under the linear ordering, where k is a positive integer and n−1/k p(n) n−1/(k+1). For each k, we give an axiomatization for the theory Tk. We find a model Mk of Tk of order type roughly that of Z and show that no other models of Tk exist of smaller size.
متن کاملRemarks on almost-sure theories of Fraïssé classes
In addition to demonstrations that certain concrete classes have 0,1-laws, there are a few general sufficient conditions now known guaranteeing that an א0-categorical theory is the almost-sure theory of some Fraïssé class – for example [3] and [16]. In this paper, we work on the converse project: determining what almost-sure theories must be like. We prove two theorems within this project. In t...
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ژورنال
عنوان ژورنال: Annals of Mathematical Logic
سال: 1980
ISSN: 0003-4843
DOI: 10.1016/0003-4843(80)90014-5