We study when a union of saturated models is saturated in the framework of tame abstract elementary classes (AECs) with amalgamation. We prove: Theorem 0.1. If K is a tame AEC with amalgamation satisfying a natural definition of superstability (which follows from categoricity in a high-enough cardinal), then for all high-enough λ: (1) The union of an increasing chain of λ-saturated models is λ-...

This paper continues the examination of the structure of pseudocomplemented distributive lattices. First, the Congruence Extension Property is proved. This is then applied to examine properties of the equational classes ¿Sn, — lá«So), which is a complete list of all the equational classes of pseudocomplemented distributive lattices (see Part I). The standard semigroups (i.e., the semigroup gene...

Combinatorial structures have been considered under various orders, including substructure order and homomorphism order. In this paper, we investigate the homomorphic image order, corresponding to the existence of a surjective homomorphism between two structures. We distinguish between strong and induced forms of the order and explore how they behave in the context of different common combinato...

Let M1 and M2 be compact, orientable 3-manifolds, and M the manifold obtained by gluing some component F of ∂M1 to some component of ∂M2 by a homeomorphism φ. We show that when φ is “sufficiently complicated” then (1) the amalgamation of low genus, unstabilized, boundary-unstabilized Heegaard splittings of Mi is an unstabilized splitting of M , (2) every low genus, unstabilized Heegaard splitti...

For a sequence of stochastic processes the aggregated process, that is a process for which the transition rates are an amalgamation of the transition rates of the processes in the sequence, is introduced. A sufficiënt condition is given, called cross-balance, a generalization of global balance to a sequence of processes, under which the equilibrium distribution of the aggregated process is show...

We propose a scheme for rule amalgamation based on nested graph predicates. Essentially, we extend all the graphs in such a predicate with right hand sides. Whenever such an enriched nested predicate matches (i.e., is satisfied by) a given host graph, this results in many individual match morphisms, and thus many “small” rule applications. The total effect is described by the amalgamated rule. ...

A graph product is the fundamental group of a graph of groups. Amongst the simplest examples are HNN groups and free products with amalgamation. The torsion and conjugacy theorems are proved for any group presented as a graph product. The graphs over which some graph product has a solvable word problem are characterised. Conditions are then given for the solvability of the word and order proble...

An amalgamation base p in a simple theory is stably definable if its canonical base is interdefinable with the set of canonical parameters for the φ-definitions of p as φ ranges through all stable formulae. A necessary condition for stably definability is given and used to produce an example of a supersimple theory with stable forking having types that are not stably definable. This answers neg...

We introduce the concept of a locally finite abstract elementary class and develop the theory of excellence (with respect to disjoint ( , k)-amalgamation) for such classes. From this we find a family of complete L!1,! sentences r that a) homogeneously characterizes @r (improving results of Hjorth [12] and Laskowski-Shelah [14] and answering a question of [22]), while b) the r provide the first...

The rapid depletion of high-grade rare earth elements (REE) resources implies that future supplies may be augmented with low-grade ores, tailings, and other unconventional to meet cut-off grades and, subsequently, supply demands. This paper presents an amalgamation studies conducted on selected complex iron-oxide-silicate-rich the overall aim developing efficacious methods associated process mi...