A partial order where all monotone maps are definable
It is consistent that there is a partial order (P,≤) of size such that every monotone function f:P → P is first order definable in (P,≤).
A Possible Characterization of Generic Structures.
A proof of Saffe's conjecture
A proof of the valuation property and preparation theorem
The purpose of this article is to present a short model-theoretic proof of the valuation property for a polynomially bounded o-minimal theory T. The valuation property was conjectured by van den Dries, and proved for the polynomially bounded case by van den Dries-Speissegger and for the power bounded case by Tyne. Our proof uses the transfer principle for the theory (i.e. T with an extra unary symbol denoting a proper convex subring), which-together with quantifier elimination-is due to van den...
A property of stable theories
A property of the solvable radical in finitely decidable varieties
It is shown that in a finitely decidable equational class, the solvable radical of any finite subdirectly irreducible member is comparable to all congruences of the irreducible if the type of the monolith is 2. In the type 1 case we establish that the centralizer of the monolith is strongly solvable.
A propos d'un théorème de MacIntyre
A reflection phenomenon in descriptive set theory
A remark on accessible and axiomatizable categories
For categories with equalizers the concepts ``accessible'' and ``axiomatizable'' are equivalent. This results is proved under (in fact, is equivalent to) the large-cardinal Vopěnka's principle.
A remark on Ax's theorem on solvability modulo primes.
A representation of models of Peano arithmetic
A representation theorem for Post-like algebras
A rigid Boolean algebra that admits the elimination of Q21
Using ♢ , we construct a rigid atomless Boolean algebra that has no uncountable antichain and that admits the elimination of the Malitz quantifier .
A saturation property on ideals
A scoop from groups: equational foundations for loops
Groups are usually axiomatized as algebras with an associative binary operation, a two-sided neutral element, and with two-sided inverses. We show in this note that the same simplicity of axioms can be achieved for some of the most important varieties of loops. In particular, we investigate loops of Bol-Moufang type in the underlying variety of magmas with two-sided inverses, and obtain ``group-like'' equational bases for Moufang, Bol and C-loops. We also discuss the case when the inverses are only...
A simple tree and its application to a counterexample of Philips.
A splitting theorem for ℱ-products
A sufficient condition for a variety to have the amalgamation property
A ternary variety generated by lattices
A theorem on generic intersections in an o-minimal structure
Consider a transitive definable action of a Lie group G on a definable manifold M. Given two (locally) definable subsets A and B of M, we prove that the dimension of the intersection σ(A) ∩ B is not greater than the expected one for a generic σ ∈ G.